Graham, David T., author
Prentice-Hall, 2000
Buku Teks
Harris, Phillip M., author
[American Society for Training & Development Press, ], 2002
eBooks
Elengolds, Linda J., author
[American Society for Training & Development Press, American Society for Training & Development Press], 2001
eBooks
Espich, James E.,
Fearon Publishers, 1967
Buku Teks
Roesel, Catherine E.
McGraw-Hill, 1978
Buku Teks