Ratzel,, . F. (1989). History of mankind: Vol.2. Radha Publication.
Chicago Edition CitationRatzel,, Friedrich. History of Mankind: Vol.2. Delhi: Radha Publication, 1989.
Cita MLARatzel,, Friedrich. History of Mankind: Vol.2. Radha Publication, 1989.
Atenció: Aquestes cites poden no estar 100% correctes.