Webber, Ross A., author
Richard D. Irwin, 1981
Buku Teks
Moonman, Eric, author
Pan Books, 1971
Buku Teks
Estep, Tora, author
American Society for Training & Development, 2006
eBooks
Blake, Robert R., author
Dow Jones-Irwin, 1980
Buku Teks
Stewart, Rosemary, author
Prentice-Hall, 1982
Buku Teks