Tim R. New, editor
[, Springer], 2012
eBooks
Nehrt, Lee Charles
Bureau of Business Research, Indiana University, 1970
Buku Teks SO
Jansson, Bruce S.
Thompson, 2005
Buku Teks
Reynolds, Paul Davidson
Prentice-Hall, 1982
Buku Teks SO
edited by Sugata Dasgupta
Impex India, 1967
Buku Teks SO