Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.

APA Citation Edition Citation

Steffen, H. (1977). 1977 Photomap [Jemen]: Approx. 1:25'000,Dimnat al Khadir, Yemen Arab Republic. Swiss Technical Co-operaton Service.

Chicago Citation Edition Citation

Steffen, Hans. 1977 Photomap [Jemen]: Approx. 1:25'000,Dimnat Al Khadir, Yemen Arab Republic. Berne: Swiss Technical Co-operaton Service, 1977.

MLA Citation Edition Citation

Steffen, Hans. 1977 Photomap [Jemen]: Approx. 1:25'000,Dimnat Al Khadir, Yemen Arab Republic. Swiss Technical Co-operaton Service, 1977.