Russell, Anne
Prentive-Hall, 1982
Buku Teks
by Cal M. Lague [and others]
Allyn and Bacon, 1982
Buku Teks
Pitt, Gavin A., author
Prentice-Hall, 1959
Buku Teks
Yerbury, Hilary, author
University of Technology, 1992
Buku Referensi
Bruce, Anne, author
American Society for Training & Development, 2008
eBooks