APA (7th ed.) Citation

Keller, C., & Wagner, H. (2008). Observatorium. W. König.

Chicago Style (17th ed.) Citation

Keller, Christoph, and Hilke Wagner. Observatorium. Köln: W. König, 2008.

MLA (9th ed.) Citation

Keller, Christoph, and Hilke Wagner. Observatorium. W. König, 2008.

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