Wragg, Ted
Routledge, 1997
Buku Teks
Oskarsson, Mats
Pergamon Press , 1980
Buku Teks
Barbera, Elena
Information Science Reference, 2014
Buku Referensi
Chapnick, Samantha
[American Society for Training & Development Press, American Society for Training & Development Press], 2000
eBooks
Dibella, Anthony J.
Prentice-Hall, 2001
Buku Teks