Burns, James McGregor, author
Prentice-Hall, 1972
Buku Teks
Burns, James McGregor, author
Prentice-Hall, 1989
Buku Teks
Punnett, R.M., author
Dartmouth, 1994
Buku Teks
Artikel Jurnal
Seckler-Hudson, Catheryn, author
United State Information Service, 1959
Buku Teks