Thonssen, Lester
D.C. Heath, 1947
Buku Teks
Bormann, Ernest G., author
Harper & Row, 1965
Buku Teks
editor, Cat Sharpe Russo
[American Society for Training and Development Press, American Society for Training and Development Press], 2005
eBooks
Bittel, Lester Robert, author
Addison-Wesley Publishing Company, Inc., 1987
Buku Teks
Mitchell, Jennifer K., author
American Society for Training & Development, 2006
eBooks