Mulgan, John, author
Clarendon Press, 1967
Buku Teks
Kennedy, X. J., author
Harper Collins College, 1991
Buku Teks
Selden, Raman, author
University Press of Kentucky, 1989
Buku Teks
Kennedy, X. J., author
Harper Collins, 1991
Buku Referensi
edited by Sylvan Barnet, Morton Berman, William Burto
Harper Collin College, 1992
Buku Teks