edited by H.H. Cole and Magnar Ronning
W.H. Freeman, 1974
Buku Teks
by Margaret J. Hartman [and others]
Kendall/Hunt, 1976
Buku Teks
Darwin, Charles, author
Oxford University Press, 2009
Buku Teks
Noble, Elmer R., author
Lea & Febiger, 1961
Buku Teks
Dillon, Lawrence S.
Macmillan Company, 1966
Buku Referensi