Ingram, Robert W., author
Thomson/South-Western, 2004
Multimedia
Ingram, Robert W., author
South-Western Publishing, 2004
Buku Teks
Knapp, Michael C., author
Ohio South-Western, 1998
Buku Teks
Harrington, Diana R., 1940-, author
The Dryden Press, 1985
Buku Teks
Hampton, John J., 1942-, author
Prentice-Hall, 1989
Buku Teks