Salvatore, Dominick, author
Prentice-Hall, 1995
Buku Teks
Spero, Joan Edelman, author
Routledge, 1994
Buku Teks
Pirages, Dennis C.
Duxbury Press, 1978
Buku Teks
Vaish, M.C.
Oxford & IBH Pub. Co., 1988
Buku Teks
Root, Franklin R., author
International Thompson Publishing, 1994
Buku Teks