May, Rollo, 1909-
W.W. Norton, 1991
Buku Teks SO
Cassirer, Ernst
Dover, 1946
Buku Teks SO
McNamee, Stephen J., 1950-
Rowman and Littlefield, 2014
Buku Teks SO
Feldman, Richard
Prentice-Hall, 1999
Buku Teks SO
Brock, Dee
John Wiley & Sons, 1978
Buku Teks SO