Doe, Norman, author
Cambridge University Press, 1990
Buku Teks
Jenks, Edward, author
John Murray, 1953
Buku Teks
Atkins, J.W.H., author
Methuen, 1951
Buku Teks
National Council for Civil Liberties with Pluto Press, 1994
Buku Teks
Stuart, Dorothy Margaret.
Macmillan, 1952
Buku Teks