Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
https://www.historikertag.de/blog/indexbe9b.html?tag=prof-dr-gilbert-lupfer
https://www.kulturgutverluste.de/Content/01_Stiftung/EN/Event-review/2016/16-11-21_conference-confiscation-of-cultural-assets-in-the-Soviet-Occupation-Zone-and-the-GDR.html
https://www.deutschland.de/en/topic/politics/20th-anniversary-of-the-washington-principles-on-tackling-nazi-looted-art