Weisinger, Hendrie, author
American Management Association, 2000
eBooks
Hasemer, Tony, author
Addison-Wesley, 1984
Buku Teks
Peale, Norman Vincent, 1898-1993, author
Prentice-Hall, 1954
Buku Teks
Ruffa, Stephen A., 1961- , author
American Management Association, 2008
eBooks
Frederika Antoinette Ketting Olivier, author
Fakultas Psikologi Universitas Indonesia, 2016
UI - Tesis (Membership)