Perl, Philip.
Time-Life Books, 1979
Buku Referensi
Leonard, Jonathan Norton, author
Time-Life International, 1974.
Buku Teks
Simons, Gerald.
Time-Life Internationa, 1968
Buku Teks
Atwood, Margaret, author
Mcclelland and Stewart, 1979
Buku Teks
Dobzhansky, Theodosius, author
John Wiley, 1955
Buku Teks