Frank, Frederick S.
Garland Publishing, 1987
Buku Referensi
Thomson, Helen
Thomas Nelson and Sons Ltd, 1993
Buku Teks SO
edited by Arthur Waldhorn, Olga S. Weber, Arthur Zeiger
R.R. Bowker, 1990
Buku Teks SO
Saricks, Joyce G.
[American Management Association, ], 2009
eBooks
McCallum, George P
Thomas Nelson and Sons Ltd, 1993
Buku Teks SO