Prata, Stephen, author
Sams Publishing , 1987
Buku Teks
McClelland, Deke, author
Destop Pub. Library, 1989
Buku Teks
Lowery, Joseph W.
IDG Books Worldwide, Inc., 1999
Buku Referensi
Macek, Rosanne M.
Meckler Corporation, 1988
Buku Referensi
Rosenbaum, Daniel J., author
McGraw-Hill, 1988
Buku Teks