Bradgate, Robert
Butterworth, 1991
Buku Teks
Simpson, Laurence P.
Alexander Hamilton Institute, 1961
Buku Teks
Stephenson, Graham
Blakstone Press, 1995
Buku Teks
Adams, Kristen David
St. Paul, MN : West Group, 2010
Buku Teks
Macintryre, Ewan
Blackstone Press, 1998
Buku Referensi