edited by C.P. Ager
Bowker-Saur, 1992
Buku Referensi
Rivoli, Pietra, author
John Wiley & Sons, 2005
Buku Teks
Department of Foreign Affairs and Trade , 1999
Buku Teks
Roemer, John E
Institute of International Studies, University of California, 1975
Buku Teks
Josling, Tim, 1940-, author
World Scientific, 2015
Buku Teks