Ratzel,, . F. (1989). History of mankind: Vol.2. Radha Publication.
Chicago Edition CitationRatzel,, Friedrich. History of Mankind: Vol.2. Delhi: Radha Publication, 1989.
MLA引文Ratzel,, Friedrich. History of Mankind: Vol.2. Radha Publication, 1989.
警告:这些引文格式不一定是100%准确.