Garland, Eric, author
American Management Association, 2007
eBooks
Adams media Corporation, 1996
Multimedia
Diamond, Jared, author
Viking, 2012
Buku Teks
swedia : Dag Hammarskjold Foundatioan, 2006,
Majalah, Jurnal, Buletin
Hall, J. Storrs, author
Prometheus Books, 2005
Buku Teks