J. Whitaker & Sons, 1995
Buku Referensi
Library Association, 1989
Buku Referensi
Park, Patricia
Kluwer Law International, 2012
Buku Teks SO
Collins, Lawrence
Butterworth, 1990
Buku Teks SO
London: Her Majesty's Stationary office, 1987,
Buku Referensi