De Blij, Harm J., author
John Wiley & Sons, 1997
Buku Teks
Armstrong, Charles K., author
Charles K. Amstrong, 2007
Buku Teks
Teik, Khoo Boo, author
Aed Book, 2003
Buku Teks
The Johns Hopkins University Press, 1995
Buku Teks
The University of North Carolina Press, 1987
Buku Teks