Gower, 1990
Buku Referensi
Baldwin, David A. (David Allen), author
Libraries Unlimited, 2003
Buku Referensi
Singer, Paula M., author
[American Management Association, ], 2009
eBooks
Schomburg, Dietmar
Springer-Verlag, 1990
Buku Referensi
Novack, Clare, author
[American Society for Training & Development Press, American Society for Training & Development Press], 2001
eBooks