Perpeloncoan Berdasarkan Fakta Sejarah adalah Warisan Ideologi Realisme - Sosialis (Fasis - Komunis)

(4) Charles Robert Darwin, 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray.

(5) Epigenetic evolution. Reference to J.B. Lamarck.

(6) Willmott, H.P. (2003), World War I, New York: Dorling Kindersley, ISBN 0-7894-9627-5, OCLC 52541937.

(7) Sommerville, Donald (2008). The Complete Illustrated History of World War Two: An Authoritative Account of the Deadliest Conflict in Human History with Analysis of Decisive Encounters and Landmark Engagements. Lorenz Books. p. 5. ISBN 0-7548-1898-5.

(8) The black book of communism, Harvard Univ Press, 1999.