edited by Eric Oey
APA Publications , 1990
Buku Referensi
Dalton, Bill
Odyssey Guides , 1991
Buku Referensi
Zelletin, Gerda
Bildungswerk Europaische Politik, 1973
Buku Teks
Speed, F.W.
Angus and Robertson , 1971
Buku Teks
edited by John S. Major
Westview Press, 1986
Buku Teks