Parnell, John E., author
Prentice-Hall, 1984
Buku Teks
editor, R. Yugo Kartono Isal
Faculty of Computer Science Universitas Indonesia, 2010
Buku Teks
VNU Business Publications, 1989
Buku Referensi
Brown, Larry Dale, author
Research and Education Association, 1994
Buku Teks
Hatim, Basil, author
Routledge, 2004
Buku Teks