Washington : Pan American Union, General Secretariet of the Organization of American States
Majalah, Jurnal, Buletin
Green Press, 2003
Buku Teks
New York : NACLA
Majalah, Jurnal, Buletin
Bannon, John Francis
McGraw-Hill, 1952
Buku Teks
Maddex, Robert L.
London: Routledge, 1995,
Buku Referensi