Burke, Barlow, author
West Publishing, 1993
Buku Teks
Findley, Roger W., author
West Publishing, 1992
Buku Teks
Bruce, Jon W., author
West Publishing, 1991
Buku Teks
Ripley, William Z.
Little, Brown, and Company, 1927
Buku Teks
Gellhorn, Ernest, author
West , 1994
Buku Teks