Marvin, Philip Roger
New York, N.Y. AMACOM c.1980,
Buku Teks
Nollen, Stanley D.
New York Amacon c.1978,
Buku Teks
Publishing Science Group, Inc., 1973
Buku Teks
Falcone, Paul
[American Management Association;, ], 2002
eBooks
Muchdis
Balai Pustaka, 1950
Buku Teks