Routledge, 1997
Buku Teks
Russell, Susan, author
[American Society for Training and Development Press, American Society for Training and Development Press], 1999
eBooks
American Bar Center, 1977
Buku Teks
Andrews, Kenneth R., author
Harvard University , 1966
Buku Teks
Clardy, Alan, author
Amacom, 2012
Buku Teks