Allen, Michael
Blackstone Press Ltd., s.a.
Buku Teks
Gunther, Gerald, author
Foundation Press, 1973
Buku Teks
Abernathy, Charles F., author
St. Paul Minn., 2000
Buku Teks
Gunther, Gerald, author
Foundation Press, 1979
Buku Teks
Cappeletti, Mauro
The Bobbs - Merrill Company,INC, 1979
Buku Teks