Cornog, Mary Wood
Springfield:Massachusetts Merriam-Webster, 1994,
Buku Teks
Cornog, Mary Wood, author
Merriam-Webster Inc., 1994
Buku Referensi
Beijing Beijing Yuyan Wenhua Daxuie Chubanshe 2000
Buku Referensi
Mackie, Benita, author
Upper Saddle River,N.J. Prentice Hall 1995,
Buku Teks
New York : Holt, Rinehart and Winston, 1995,
Buku Teks