Earl, Michael J.
Prentice-Hall, 1989
Buku Teks SO
edited by Paul J.J. Welfens
Springer, 2012
eBooks
Harries, Steve
Library Assocantion Publishing, 1993
Buku Teks SO
Idea Group Publishing, 2004
Buku Teks SO
Turban, Efraim, 1930-
John Wiley & Sons, 2015
Buku Teks SO