Soderquist, Larry D.
The Michie Company, 1991
Buku Teks
Dodd, E. Merrick, author
Foundation Press, 1951
Buku Teks
Hamilton, Robert W., author
West Publishing, 1990
Buku Teks
Burke, Barlow, Jr.
St. Paul, Minn, 1994
Buku Teks
Whaley, Douglas J.
Little, Brown & Co., 1993
Buku Teks