https://www.openpetition.de/petition/online/rettet-das-theatermuseum-duesseldorf
Von Photo: Andreas Praefcke – Eigenes Werk (own photograph), CC BY 3.0, Link
https://www.openpetition.de/petition/online/rettet-das-theatermuseum-duesseldorf
Von Photo: Andreas Praefcke – Eigenes Werk (own photograph), CC BY 3.0, Link