Bateman, Thomas S.
McGraw-Hill, 1999
Buku Teks
Narayanan, V. K.
Prentice Hall 2001, 2001
Buku Teks SO
ed. by Nick Boulter, Murray Dalziel and Jackie Hill ; foreword by David McClelland
Crest Publishing House, 1999
Buku Referensi
Porter, Michael E.
The Free Press , 1990
Buku Teks SO
Pinto, Jeffrey K.
Pearson Prentice Hall, 2007
Buku Teks SO