Gardner, Howard
Basic Books, 1983
Buku Teks
Overstreet, H.A.
W.W Norton & Company, Inc, 1959
Buku Teks
Cairns-Smith, A.G.
Cambridge University Press, 1996
Buku Teks
Sagan, Carl
Presidio Press, 1980
Buku Teks
Hedgecoe, Mark.
BBC Worldwide Limited, 2005
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