Wessells, Michael
Harvard University Press, 2006
Buku Teks
Gammage, Bill
Penguin Books, 1990
Buku Teks SO
Parker, John
Headline, 2005
Buku Teks
edited by Elizabeth Bennett, Virginia Gamba, Dierdré van der Merwe
Institute for Security Studies, 2000
Buku Teks SO
Barrett, John
Allen & Unwin, 1995
Buku Teks SO