Bartono P. H., author
Andi, 2005
Buku Teks
Wuest, Deborah, author
McGraw-Hill, 2012
Buku Teks
Tieger, Paul D., author
Litle, Brown, 2014
Buku Teks
Lowen, Walter
Greystone Press, 1958
Buku Teks
Simonsen, Peggy, author
American Society For Training & Development;, 1995
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