Maynard, Lee
New York Washington Square Press 1988
Buku Teks
edited by Kjell B. Zandin
McGraw-Hill, 2001
Buku Referensi
Maynard, Mary, editor
Longman, 1993
Buku Teks
edited by Kjell B. Zandin
McGraw-Hill, 2001
Buku Referensi
William K. Hodson, editror-in-chief
McGraw-Hill, 1992
Buku Referensi