Gedes & Grosset, 2003
Buku Referensi
University of Technology Sydney
Lovell Johns , 1996
Buku Referensi
Rand McNally, editor
Time-Life Books, 1968
Buku Referensi
Pereltsvaig, Asya, 1972-, author
Cambridge University Press, 2012
Buku Teks
edited by Bernard Comrie
Routledge, 1991
Buku Referensi