Mace, Myles L.
Harvard University , 1950
Buku Teks
Norcross, Harold, author
Pan Books, 1971
Buku Teks
Hague, Hawden, author
Macmillan, 1974
Buku Teks
Lisa Haneberg, editor
American Society for Training & Development, 2012
eBooks
Prerau, Sydney, author
McGraw-Hill, 1960
Buku Teks