Cita APA (7th ed.)
Köster, E., & Leser, H. (1967). Geomorphologie. Westermann.
Cita Chicago (17th ed.)
Köster, Erhard, i Hartmut Leser. Geomorphologie. Braunschweig: Westermann, 1967.
Cita MLA (9th ed.)
Köster, Erhard, i Hartmut Leser. Geomorphologie. Westermann, 1967.
Atenció: Aquestes cites poden no estar 100% correctes.