Gilmore, John V
Albion Publishing Company, 1974
Buku Teks SO
Falcone, Paul
American Management Association, 2007
eBooks
Clements-Crome, editor
E & FN Spon, 2000
Buku Teks SO
Murphy, Lawrence R.
Taylor and Francis, 2000
Buku Teks
Nakajima, Seiichi
Productivity Press, 1988
Buku Teks SO