Burton, Graeme
McGraw-Hill, 2010
Buku Teks
Clark, Ruth Colvin
American Society for Training & Development, 2010
eBooks
Ruth Colvin Clark
ASTD Press, 2010
Buku Teks
Clark, Ruth Colvin
VA ATD Press, 2015
Buku Teks
Hammersley, Martyn
Longman , 1990
Buku Teks