Harry N. Abrams, INC, 2001
Buku Teks
Irwin, Keith Gordon
homas Y. Crowell, 1963
Buku Teks
Anthony, Michael
Houghton Mifflin, 1967
Buku Teks
Scott, Gini Graham, author
American Management Association, 2007
eBooks
Welles, Chris
E.P. Dutton & Co., 1975
Buku Teks