MacIver, Robert M.
Atherton Press, 1969
Buku Teks
edited by Stephen White, Judy Batt and Paul G. Lewiss
Macmillan, 1993
Buku Teks
Nugent, Neill
Macmillan, 1994
Buku Teks
Daltrop, Anne
Longman, 1982
Buku Teks
Wiarda, Howard J.
Hartcourt College Publishers, 2001
Buku Teks