Gilbert, Sara D.
McGrw-Hill, Inc. , 1993
Buku Teks
Gilbert, Sara
Sage Publications, 2000
Buku Teks
Reinhold Publishing Corporation, 1961
Buku Teks
Mel Silberman, editor
American Society for Training & Development, 2005
eBooks
Mel Silberman, editor; Patricia Phillips, assistant editor
American Society for Training & Development, 2006
eBooks