Mitton, Maureen
John Wiley & Sons, [Date of publication not identified]
Buku Teks SO
Leach, Sid DelMar
McGraw-Hill, 1983
Buku Teks SO
Pile, John F.
H.N. Abrams, 1995
Buku Teks SO
Massachusetts: Rockport Publishers,, 1997
Buku Teks SO
Drew, Philip, 1943-
Law Book Company Limited, 1985
Buku Referensi