Ruth Colvin Clark
ASTD Press, 2010
Buku Teks
Clark, Ruth Colvin
VA ATD Press, 2015
Buku Teks
Prentice, William E.
McGraw-Hill Education , 2017
Buku Teks
Linsley, Paul
Sage, 2019
Buku Teks
edited by Andrew Booth and Anne Brice
Facet Publishing, 2004
Buku Referensi