Hall, Kermit L.
Oxford University Press, 1991
Buku Teks
Mashaw, Jerry L
Thomson/West, 2009
Buku Teks
Merryman, John Henry
Bobbs-Merril, 1978
Buku Teks
Schlesinger, Rudolf B.
The Foundation Press, 1950
Buku Teks
Kauper, Paul G.
Little, Brown, 1971
Buku Teks