Borland International, 1988
Buku Teks
Hinkle, Deborah A.
MCGraw-Hill , 2002
Multimedia
HInkle, Deborah, author
Glencoe/McGraw-Hill , 2002
Buku Teks
MicroPro International Corporation , 1988
Buku Teks
Foreman, Patricia L.
Good Earth Publications , 1992
Buku Teks