Kaplan, Burton, author
Prentice-Hall, 1995
Buku Teks
Steinmetz, Ralf, author
River Prentice-Hall , 1995
Buku Teks
Parkman, Henry P., editor
Springer, 2012
eBooks
Plattner, Francis B., author
American Society for Training and Development Press, 1997
eBooks
Artikel Jurnal