APA (7th ed.) Citation

Seelmann, G., Giger, A., & Kalmár, M. (1979). Spazieren in Berlin. Stapp.

Chicago Style (17th ed.) Citation

Seelmann, Gabriele, Artur Giger, and Michael Kalmár. Spazieren in Berlin. Berlin: Stapp, 1979.

MLA (8th ed.) Citation

Seelmann, Gabriele, et al. Spazieren in Berlin. Stapp, 1979.