Walker, Patrick Gordon, author
Hutchinson & Company, 1951
Buku Teks SO
Bonell, Michael, author
Transnational Juris Publications, 1994
Buku Teks
Handlin, Oscar, author
Atheneum, 1966
Buku Teks
Mill, John Stuart, author
David Campbell Publisher, 1992
Buku Referensi
Walker, Marianne McGettigan
American law Institute Publishers, 1995
Buku Teks