Casamassima, Christy
PBC International, 1998
Buku Teks
Kaplan, Michael
PBC International, 1997
Buku Referensi
Cohen, Edie Lee
Cahners, 1984
Buku Teks
Mary Kupiec Cayton, Elliott J. Gorn, Peter W. Williams, editors
Charles Scribner's Sons, 1993
Buku Referensi
Leflar, Robert A.
The Michie Company, 1986
Buku Teks