Goodyear Publishing Company, Inc., 1973
Buku Teks
Gaedeke, Ralph M., author
Canfield Press , 1972
Buku Teks
American Enterprise Institute for Public Policy Research, 1979
Buku Teks
Mowen, John C.
Prentince Hall, 1995
Buku Teks
Mowen, John C., author
Prentice-Hall, 1998
Buku Teks