Roethlisberger, F.J.
Harvard University Press , 1959
Buku Teks
Roethlisberger, F.J.,
Aksara Baru, [1941]
Buku Teks
An Aspen Publication, 1985
Buku Teks
Haneberg, Lisa
American Society for Training & Development, 2011
eBooks
Deaux, Kay
Brooks/Cole, 1983
Buku Teks