Long, Lori, author
[American Society for Training and Development Press, American Society for Training and Development Press], 2000
eBooks
Schrauf, Robert W, author
Cambridge University Press, 2016
Buku Teks
by H.G. Johnson... [and others]
Macmillan, 1968
Buku Teks
Linda B. Bourque, Evie P. Filelder
Thousand Oaks : SAGE PUBLIKATION, 2003,
Buku Referensi
Althaus, Scott L., author
Cambridge University Press, 2003
Buku Teks