Phillips, Jack J.
Jossey-Bass Publishers, 1987
Buku Teks
Griffeth, Rodger
Sage Publications , 2001
Buku Teks
Halsey, George D.
Harper & Brothers, 1949
Buku Teks
Hickman, E. Stewart
[American Society for Training & Development Press, American Society for Training & Development Press], 2000
eBooks
Levesque, Joseph D.
Prentice-Hall, 1996
Buku Referensi