Klooster, Dale H., author
South-Western, 1990
Buku Teks
Klooster, Dale H., author
South-Western Publishing, 1983
Buku Teks
Page, John R., 1949-, author
Reston Publishing, 1985
Buku Teks
Gillis, M. Atrhur
Dow Jones-Irwin, 1985
Buku Teks
Hearing, Sylvia, 1954-
Regents/Prentice Hall, 1994
Buku Teks