Gregory, William A., author
West, c2009
Buku Teks
Crane, Judson
West Publishing Co., 1952
Buku Teks
Hamilton, Robert W., author
West Publishing, 1990
Buku Teks
Hynes, J. Dennis, author
The Bobbs-Merill Company, 1974
Buku Teks
Hynes, J. Dennis, author
The Michie Company, 1994
Buku Teks