Stryker, Perrin, author
McGraw-Hill, 1954
Buku Teks
Dale, Ernest, author
Penguin Books, 1975
Buku Teks
Haimann, Theo, author
Houghton Mifflin, 1974
Buku Teks
edited by Albert Newgardsen
American Management Association, 1959
Buku Teks
Makridakis, Spyros G., author
John Wiley & Sons, 1989
Buku Teks