Garrison, Catherine, author
Reading, Mass Addison-Wesley Publishing Co , 1989
Buku Teks
Lotus, [date of publication not identified]
Buku Teks
edited by Thomas van Raalte
O`Reilly, 1990
Buku Teks
Fraser, W.
Macdonald and Jane's, 1978
Buku Teks
Markus, John, 1911-, author
McGraw-Hill, 1980
Buku Referensi