Horton, William
ASTD Press, 2001
Buku Teks
edited by Fred Kiesner
World Scientific, 2010
Buku Teks
Odiorne, George S.
WED International, [Date of publication not identified]
Buku Teks
edited by J. Timothy Harrington and Eric D. Newman
Springer, 2012
eBooks
Hersey, John
Alfred A. Knopf, 1963
Buku Teks