Παραπομπή APA

Ratzel,, F. (1989). History of mankind: Vol.1. Radha Publication.

Παραπομπή Chicago Style

Ratzel,, Friedrich. History of Mankind: Vol.1. Delhi: Radha Publication, 1989.

Παραπομπή MLA

Ratzel,, Friedrich. History of Mankind: Vol.1. Radha Publication, 1989.