Callahan, Madelyn R.
ASTD Press, 2006
eBooks
Gendelman, Joel
ASTD Press, 2010
eBooks
Bayu Perkasa Temadja
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2010
UI - Tesis Open
Rehan Wira Widyatna
Fakultas Teknik Universitas Indonesia, 2021
UI - Skripsi Membership
Cope, Mick
Financial Times, Prentice-Hall, 2003
Buku Teks SO