Hayes, Tom, author
McGraw-Hill, 2008
Buku Teks
Laurel, Deborah Spring, author
American Society for Training & Development, 2008
eBooks
Maxwell, John C., author
NY : Center Street, 2014
Buku Teks
Marks, Harry, author
Thomas Nelson, 1976
Buku Teks
See, Lisa, author
Blanvalet, 2007
Buku Teks