Austin, Richard L., author
Van Nostrand Reinhold, 1983
Buku Teks
Nunan, David , author
Cambrigde University Press , 1993
Buku Teks
editor by Dabid A. Harris, Byron W. Engen and William E. Fitch
Van Nostrand Reinhold, 1991
Buku Teks
Entwistle, Jill, author
Roto Vision SA, 2000
Buku Referensi
Landis, Dylan, author
PBC International, 1996
Buku Referensi