Coulton, G.G. (George Gordon), author
Macmillan; University Press, 1938
Buku Teks
Miller, Roger LeRoy, author
West Educational Publishing, 1999
Buku Teks
Smith, J. C. (James Cruickshanks), 1867-1946, author
Sweet & Maxwell, 1989
Buku Teks
Slapper, Gary, author
Cavendish Publishing Limited, 2000
Buku Teks
Keenan, Denis, author
Pitman, 1992
Buku Teks