Flenning, Peter
Megapoin, 1996
Buku Teks
Shin, Edysen, author
Alfa Cemerlang Edindo (AceLearnings), 2016
Buku Teks
Tracy, Brian, author
American Management Association, 2013
eBooks
Roy J. Lewicki [and others]
McGraw-Hill, 2003
Buku Teks
Tracy, Brian, author
American Management Association, 2012
eBooks