Heaton, Russell, author
Blackstone, 1998
Buku Referensi
Sackville, Ronald, author
Butterworth, 1975
Buku Teks
Adelman, Martin J., author
Thomson/West, 2009
Buku Teks
Prosser, William L., author
Foundation Press, 1962
Buku Teks
Ratner, David L., author
West Publishing, 1996
Buku Teks