Morley, John Viscount
Watts, 1933
Buku Teks
Barrett, Maxwell
Blackstone Press Limited, 1998
Buku Referensi
Adams, John, 1938-
Butterworth, 1987
Buku Teks
Kutner, Peter B.
Greenwood Press , 1988
Buku Teks
James, Francis Edmund Skone
Sweet & Maxwell, 1958
Buku Teks