Adams, Kenneth A.
American Bar Association, 2008
Buku Teks
Chambers, Harold L.
Prentice-Hall, 1980
Buku Referensi
Hasanuddin Rahman
Citra Aditya Bakti, 2003
Buku Teks
The University of Chicago Press, 2010
Buku Teks SO
general editor, Philip Rubens
Henry Holt and Company, 1992
Buku Referensi