Leftwich, Richard H., author
Rienhard and Winston, 1969
Buku Teks
McEachern, William A., author
South-Western College Publishing, 1988
Buku Teks
Frain, H. LaRue
Hougton Mifflin Company, 1937
Buku Teks
McKenzie, Richard B., author
McGraw-Hill, 1978
Buku Teks
Quirk, James P.
McGraw-Hill, 1968
Buku Teks