APA (7th ed.) Citation

Seehusen, I., Ostländer, E., & Schade, W. (1993). Gerhard Kettner.

Chicago Style (17th ed.) Citation

Seehusen, Inga, Elke Ostländer, and Werner Schade. Gerhard Kettner. Berlin, 1993.

MLA (8th ed.) Citation

Seehusen, Inga, et al. Gerhard Kettner. 1993.