Harris, D.J.
Sweet & Maxwell, 1983
Buku Teks
Harris, D. J.
Sweet & Maxwell, 1991
Buku Teks
Dixon, Martin
Black Stone Press Limited, 1998
Buku Teks
Fenwick, Charles G., author
Callaghan and Company, 1935
Buku Teks
Cambridge University Press,
Buku Referensi