Frank Heidenreich
Direktor/Vorstandsmitglied bei Duisburger Verkehrsgesellschaft AG
Aktive Beziehungen
Name | Geschlecht | Alter | Unternehmensverbindungen | Zusammenarbeit |
---|---|---|---|---|
Dieter H. Vogel | M | 83 |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Bergit Fleckner-Olbermann | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Kerstin Schütte | F | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Michael Wischnewski | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Isabel Pfeiffer-Poensgen | F | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Hans-Georg Lohe | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Martin Murrack | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Alexandra Stampler-Brown | F | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Jörg-Thomas Alvermann | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Elmar Klein | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Yvan Caljkusic | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Edeltraud Klabuhn | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Angelika Röder | F | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Martina Stecker | F | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Ingo Möllhoff | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Hans-Peter Boschen | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Klaus-Dieter Povsic | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Jürgen Edel | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Thomas Geisel | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Udo Vohl | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Sören Link | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Frank Albrecht | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Peter Knäpper | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Marcus O. Wittig | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Friedrich G. Conzen | M | 48 |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Herbert Mettler | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Annelies Böcker | F | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Mirze Edis | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Manfred Jan Neuenhaus | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Thomas Krützberg | M | - |
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu
Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisbu Media ConglomeratesConsumer Services Deutsche Oper am Rhein Theatergemeinschaft Düsseldorf-Duisburg ggmbh is a renowned theater community based in Dusseldorf, Germany. The company is one of the large opera houses in Germany, with a long tradition of cooperation between the two cities. The private company has a high-ranking soloist ensemble, choir, and a nationally and internationally celebrated company ballet on the Rhine. The company has developed into one of the first addresses for music theater and dance in Germany. The company was founded in 1956, and the CEO is Alexandra Stampler-Brown. | - |
Karl-Heinz Staniewski | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Thomas Keuer | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Volker Rayen | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Dieter Lieske | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Heiko Blumenthal | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Karlheinz Hagenbuck | M | - |
Duisburger Verkehrsgesellschaft AG
Duisburger Verkehrsgesellschaft AG Other TransportationTransportation Duisburger Verkehrsgesellschaft AG is a transportation company based in Duisburg, DE. Duisburger Verkehrsgesellschaft is a subsidiary of the City of Duisburg and is ultimately controlled by them. The German company provides transportation services to over 165,000 passengers daily within and beyond the city limits. The company's main services include SchokoTicket and KombiTicket, and it has various ticket sales outlets and a customer center. The CEO of the company is Marcus O. Wittig. | - |
Beziehungs-Chart
Beziehungen zu mehreren Unternehmen
Statistik
Land | Beziehungen | % des Gesamten |
---|---|---|
Deutschland | 36 | 100,00% |
Alter der Beziehungen
Aktive
Vergangene
Herr
Frau
Aufsichtsräte
Führungskräfte
Ursprung der Beziehungen
- Börse
- Insiders
- Frank Heidenreich
- Persönliches Netzwerk