Laitin, David D.
The University of Chicago Press, 1986
Buku Teks
Carr, Patricia A.
American Society for Training & Development, 2006
eBooks
editor, Wiendu Nuryanti
Gadjah Mada University Press , 1996
Buku Referensi
by Janice McLaughlin, Paul Rosen, David Skinner and Andrew Webster
Routledge, 1999
Buku Teks
Joko Suwaryo
Graduate Program in Management and Business Bogor Agricultural University, 2015
Artikel Jurnal