Carley, Michael
Earthscan Publications, 1998
Buku Teks
Davis, Sid
American Management Association, 2008
eBooks
Reed, Mortimer P.
Prentice-Hall, 1983
Buku Teks
Ching, Francis D.K., 1943-
Erlangga, 1993
Buku Referensi
Ching, Francis D.K., 1943-
Erlangga, 1983
Buku Teks SO