Buzan, Tony
Penguin Books, 1991
Buku Teks SO
Gazzaniga, Michael S.
Norton & Company, 2003
Buku Teks SO
edited by Donna Coch, Kurt W. Fischer, Geraldine Dawson
Guilford Press, 2007
Buku Teks
Lucas, Bob
American Management Association, 2008
eBooks
edited by J. Graham Beaumont
Grange Books, 1989
Buku Referensi