Nollen, Stanley D.
New York Amacon c.1978,
Buku Teks
Marvin, Philip Roger, author
New York, N.Y. AMACOM c.1980,
Buku Teks
Cohen, Allan R., author
Addison-Wesley Pub. Co., 1978
Buku Teks
American Management Association , 1986
Buku Teks
Martin, Shan
Sage Publications, 1983
Buku Teks