Summer, Charles E., author
Little, Brown, 1980
Buku Teks
Christensen, Ralph, author
American Management Association, 2006
eBooks
Gamble, John, author
McGraw-Hill , 2015
Buku Teks
David, Fred R., author
Pearson, 2015
Buku Teks
Verardo, Denzil, author
[American Society for Training and Development Press, American Society for Training and Development Press], 1999
eBooks