Clayton, James E.
E.P. Dutton, 1964
Buku Teks
Cox, Archibald, 1912-2004
Oxford University Press, 1976
Buku Teks
McCloskey, Robert G.
University of Chicago Press, 1962
Buku Teks
Johnson, Gerald W.
William Morrow, 1962
Buku Teks
Bickel, Alexander M.
Harper & Row, 1970
Buku Teks