Kampourakis, Kostas, author
Cambridge University Press, 2014
Buku Teks
Prothero, Donald R.
McGraw-Hill Higher Education, 2004
Buku Referensi
Axelrod, Robert M., author
Basic Books, 1984
Buku Teks
edited by Anne Roe and George Gaylord Simpson
Yale University Press, 1961
Buku Teks
Pilbeam, David, author
Funk and Wangnalls, 1970
Buku Teks