Routledge, 1996
Buku Teks
Craven, Paul R., author
Dickenson Publishing, 1968
Buku Teks
Stauffer, Donald Alfred, author
Princeton University Press, 1941
Buku Teks
Conway, Jill Ker
Apfred A. Knopf, 1998
Buku Teks
Departemen Pendidikan dan Kebudayaan, 1982
Buku Teks