Koch, Edward T., author
Kencana Prenada Media Group, 2008
Buku Teks
Parry, Julie, author
Librry Association Publishing, 1993
Buku Teks
Passante, Christopher K., author
Prenada Media Group, 2008
Buku Teks
Grossman, Charles J., author
Sulzburger & Graham, 1995
Buku Teks
England Longman 1983
Buku Referensi