Mcnamee, Patrick
Heinemann , 1988
Buku Teks
Maclagan, Patrick
Sage, 1998
Buku Teks
Elex Media Komputindo , 1990
Buku Teks
Vangundy, Arthur B., author
American Management Association, 2007
eBooks
Crane, Burton
Harcourt, Brace and Company, 1956
Buku Teks