White, Ron
Prentice Hall International English Language Teaching , 1994
Buku Teks
Musolf, Lloyd D.
Scott, Foresman and Company, 1965
Buku Teks
Cain, Brian
Grolier International, 1999
Buku Teks
Mantu, Poppie Indriyanti
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2003
UI - Tesis Membership
Cain, Brian
Glorier International, 1999
Buku Referensi