Munson, Lawrence R.
McGraw-Hill, 1984
Buku Teks SO
Sabine Mertens Oishi
Thousand Oaks : SAGE PUBLIKATION, 2003,
Buku Referensi
editor, Cat Sharpe
[American Society for Training and Development Press, American Society for Training and Development Press], 1997
eBooks
Angus, Helen
Arcan, 1996
Buku Teks
Linda B. Bourque, Evie P. Filelder
Thousand Oaks : SAGE PUBLIKATION, 2003,
Buku Referensi