Warr, George, author
Sweet & Maxwell, 1994
Buku Teks
Phelan, Margaret
Blakstone Press Limited, 1997
Buku Teks
Supperstone, Michael, author
Longman, 1994
Buku Teks
Boswell, Richard A., author
Carolina Academic Press, 1992
Buku Teks
Maideus, Melinda
Facts on File, 1981
Buku Teks