Moncrieff, Gladys
Rigby, 1971
Buku Teks SO
Markus, John, 1911-
McGraw-Hill, 1994
Buku Referensi
edited by Abel Albet, Nuria Benach
Routledge, 2018
Buku Teks SO
Harris, Robert, editor
Faber and Faber, 1984
Buku Teks SO
De Montfort University Law Monographs Cavendish Publishing Limited, [date of publication not identified]
Buku Teks SO