Caplovitz, David, author
Free Press; Collier-Macmillan, 1967
Buku Teks
Leinwand, Gerald
Washington Square Press, 1970
Buku Teks
Katona, George
McGraw-Hill Book , 1960
Buku Teks
Mowen, John C.
Prentince Hall, 1995
Buku Teks
Mowen, John C., author
Prentice-Hall, 1998
Buku Teks