Hamilton, Robert W.
Little, Brown and Company, 1989
Buku Teks
Howell, Rate A., author
The Dryden Press, 1984
Buku Teks
Globerman, Steven
Prentince-Hall, 1986
Buku Teks
Miller, Roger LeRoy, author
Thomson West, 2007
Buku Teks
Corley, Robert Neil, author
Prentice-Hall, 1974
Buku Teks