Nendeln : The Association of American Geographers
Majalah, Jurnal, Buletin
New york, Burt Franklin and company, Inc
Majalah, Jurnal, Buletin
edited by Alan Lightman
Houghtn Mifflin, 2000
Buku Teks
Chapman, Robert L., author
London Pan Books 1988
Buku Referensi
New Slaven : American Oriental Society
Majalah, Jurnal, Buletin