Burger, Chester, author
Macmillan, 1964
Buku Teks
Russell, Susan, author
[American Society for Training and Development Press, American Society for Training and Development Press], 1999
eBooks
Clardy, Alan, author
Amacom, 2012
Buku Teks
Clardy, Alan, author
American Management Association, 2012
eBooks
World Executive's Digest, 1981
Buku Teks