Stavrianos, Leften Stavros, author
Allyn and Bacon, 1967
Buku Teks
De Blij, Harm J., author
John Wiley & Sons, 1996
Buku Referensi
Marsh, William M., author
Cambridge University Press, 2013
Buku Teks
Bradshaw, Michael, author
McGraw-Hill, 2012
Buku Teks
Bradshaw, Michael J, author
McGraw-Hill, 2012
Buku Teks