Katz, Elihu, author
Free Press, 1964
Buku Teks
Chafee, Zechariah
The University of Chicago Press, 1947
Buku Teks
Nelson, Harold L.
The Foundation Press,Inc., 1969
Buku Teks
Nelson, Harold L.
The Foundation Press,Inc., 1978
Buku Teks
Nelson, Harold L.
The Foundation Press,Inc., 1973
Buku Teks