Bean, Roger, author
AMACOM, 2002
Buku Teks
Mantyla, Karen, author
American Society for Training & Development, 2009
eBooks
Harvard Business School Press, 2003
Buku Teks
Harvard Business School Publishing Corporation, 2001
Buku Teks
Ulrich, Dave
Harvard Bussines School Press, 1996
Buku Teks