West Publishing Company, 1996
Buku Teks
Francisco, Albert K., author
Addison-Wesley, 1984
Buku Teks
Howell, Rate A., author
Dryden Press, 1988
Buku Referensi
Andrew Christie, Stephen Gare
Blackstone Press, 2001
Buku Teks
edited by. Nigel G. Foster
Nigel G.Foster, 1998,
Buku Referensi