APA (7th ed.) Citation

Ridder, H. (2019). Archivmaterialien zu Helmut Ridder, 1919-2007.

Chicago Style (17th ed.) Citation

Ridder, Helmut. Archivmaterialien Zu Helmut Ridder, 1919-2007. 2019.

MLA (9th ed.) Citation

Ridder, Helmut. Archivmaterialien Zu Helmut Ridder, 1919-2007. 2019.

Warning: These citations may not always be 100% accurate.