Watson, George
Longman, 1987
Buku Teks
Osbeck, Mark K.
Thomson/West, 2010
Buku Teks
Allard, Patsy Bailey
AMA Membership Publications Division, American Management Associations, 1983
Buku Referensi
Mauch, James E.
Marcel Dekker, Inc., 1993
Buku Teks
Hockett, Homer Carey
Macmillan, 1963
Buku Teks