Jones, Reginald L.
Taraporevala, 1966
Buku Teks
Banks, Alan, author
McGraw-Hill, 2008
Buku Teks
edited by Raymond A. Bauer, Kenneth J. Gergen
The Free Press, 1968
Buku Teks
Vickers, Geoffreyt
Basic Books, Inc., 1965
Buku Teks
Eden, Colin, author
Macmillan, 1975
Buku Teks