Johnson, Donald M.
Harper and Row, 1972
Buku Teks SO
edited by by Ai Choo Ong and Gary D. Borich
McGraw-Hill, 2006
Buku Teks
Thomson, Robert
Penguin Books, 1974
Buku Teks SO
Vinacke, Edgar W.
McGraw-Hill, 1974
Buku Teks SO
edited by Keith J. Holyoak, Robert G. Morrison
Cambridge University Press, 2005
Buku Referensi