prepared by the Cartographic Department of the Clarendon Press
Oxford University Press, 1972
Buku Referensi
Wiegand, Patrick
Oxford University Press, 1994
Buku Teks
Crawley, Angela
Oxford University Press, 1994
Buku Referensi
Oxford University Press, 1971
Buku Referensi
Carnes, W. Stansbury
HarperBusiness, 1992
Buku Referensi