APA (7th ed.) Citation

Ridder, H. Archivmaterialien zu Helmut Ridder, 1919-2007.

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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

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