Pierce, Milton
Dow Jones-Irwin, 1980
Buku Teks
Young, Dennis
The Urban Institute , 1972
Buku Teks
Sher, David
Amacom, 1999
Buku Teks
Conway, Mal
[;American Society for Training & Development Press, American Society for Training & Development Press], 2000
eBooks
edited by Santa A. Raizen, Peter H. Rossi
National Academy Press, 1981
Buku Teks