Insor, D., author
Frederick A.Praeger, 1963
Buku Teks
Windschuttle, Keith
Penguin Books, 1980
Buku Teks
Paul H. Elwood, Jeremy B. Albertus, editor
Nova Science Publisher, 2008
Buku Teks
The Habibie Center,
Majalah, Jurnal, Buletin
Senelle, Robert
Ministry of Foreign Affairs and External Trade , 1979
Buku Teks