edited by Janice McLean
Gale Research, 1991
Buku Referensi
Katcher, Bruce L.
[American Management Association;, ], 2010
eBooks
Gendelman, Joel
ASTD Press, 2010
eBooks
Cope, Mick
Financial Times, Prentice-Hall, 2003
Buku Teks SO
Reed, Thomas
ASTD Press, 2003
eBooks