edited by Geoffrey Barraclough
Times Books, 1984
Buku Referensi
The George F. Cram, 1952
Buku Referensi
prepared by the Cartographic Department of the Clarendon Press
Oxford University Press, 1972
Buku Referensi
C.S. Hammond & Company
C.S. Hammond & Company, 1958
Buku Teks
Rossi, Renzo, author
Macmillan, 1996
Buku Referensi