Marshall, Judi
Macmillan, 1979
Buku Teks
Russell, Susan
[American Society for Training and Development Press, American Society for Training and Development Press], 1999
eBooks
Andrews, Kenneth R.
Harvard University , 1966
Buku Teks
Chew, Sally
Times Books International, 1995
Buku Teks
Sanders, Thomas H.
Harvard. Univ., Press, 1951
Buku Teks