Johnston, Craig N., author
West, 2010
Buku Teks
Beatty, Jeffrey F., author
South Western Cengage Learning, 2011
Buku Teks
Buttler, Henry N.
South-Western Publishing Co., 1987
Buku Teks
Blackburn, John D., author
Richard D. Irwin , 1985
Buku Teks
Lieberman, Jethro K.
Harcourt Brace Jovanovic, 1989
Buku Teks