Petri, Herbert L
Motivation : theory, research and application
Cengage Learning, 2013
 Buku Teks
Schunk, Dale H.
Motivation in education : theory, research, and applications
Pearson Education, 2010
 Buku Teks
Schunk, Dale H.
Motivation in education: theory, research, and applications
Prentice-Hall, 1996
 Buku Teks
The Iraqi revolution : one year of progress and achivement
[publisher not identified], [date of publication not identified]
 Buku Teks
Tracy, Brian
Motivation
American Management Association, 2013
 eBooks