Roethlisberger, F.J.
Harvard University Press, 1956
Buku Teks
Gendelman, Joel, author
ASTD Press, 2010
Buku Teks
edited by Joseph F. McCloskey, Florence N. Trefethen
John Hopkins Press, 1954
Buku Teks
Cooper, Donald R., author
McGraw-Hil, 2003
Multimedia
Chorafas, Dimitris N.
Reinhold Publishing Corporation, 1958
Buku Teks