Gruber, Edward
Arc Books, 1963
Buku Teks
Hurt, Robert L.
McGraw - Hill - Irwin, 2008
Buku Teks
Niven, William
Prentice-Hall, 1964
Buku Teks
Specthrie, Samuel Waldo
Prentic-Hall , 1963
Buku Teks
American Law Institute-American Bar Association, 1988
Buku Teks