Oxford University Press, 1972
Buku Referensi
prepared by the Cartographic Department of the Clarendon Press
Oxford University Press, 1972
Buku Referensi
Wiegand, Patrick
Oxford University Press, 1994
Buku Teks
Oxford University Press, 1971
Buku Referensi
Crawley, Angela, author
Oxford University Press, 1994
Buku Referensi