APA (7th ed.) Citation

Walter, J., Knapp, E., & Krebs, A. (1977). Amphibien unserer Heimat.

Chicago Style (17th ed.) Citation

Walter, Jakob, Egon Knapp, and Albert Krebs. Amphibien Unserer Heimat. Schaffhausen, 1977.

MLA (9th ed.) Citation

Walter, Jakob, et al. Amphibien Unserer Heimat. 1977.