Crabbe, Ernest H.
South-Western Publishing, 1961
Buku Teks
Traub, J.F.
Academic Press, 1980
Buku Teks
Gratzer, George
Academic Press, 1978
Buku Teks
Boulding, Kenneth Ewart, 1910-1993
Harper, 1963
Buku Teks
Kelsen, Hans
The Lawbook Exchange, 1993
Buku Teks