Hall, Jim, author
Pluto Press, 2001
Buku Teks
Ferguson, Donald L., author
National Textbook, 1994
Buku Teks
C. Christhopher
Anmol Publicatioans PVT. Ltd, 1997
Buku Teks
Passante, Christopher K., author
Prenada Media Group, 2008
Buku Teks
Whale, John
Macmillan, 1972
Buku Teks