Robinson, Francis, author
Facts on File, 1982
Buku Referensi
Stavrianos, L.S.
Prentice-Hall, 1982
Buku Teks
Gedes & Grosset, 2003
Buku Referensi
University of Technology Sydney
Lovell Johns , 1996
Buku Referensi
Rand McNally, editor
Time-Life Books, 1968
Buku Referensi