McGraw-Hill, 1970
Buku Teks
Lisa Haneberg, editor
American Society for Training & Development, 2012
eBooks
Iaconetti, Joan, author
Macmillan, 1985
Buku Teks
Deverell, C.S., author
London, Gee & Co
Buku Teks
edited by Sidney Mailick; The United Nations Institute for Training and Research
Anchor Press, 1974
Buku Teks