Strahler, Alan H., author
John Wiley & Sons, 1997
Buku Teks SO
De Blij, Harm J., author
John Wiley & Sons, 1996
Buku Referensi
De Blij, Harm J., author
John Wiley & Sons, 1993
Buku Teks SO
Hidore, John J., author
Scott, Foresman, 1974
Buku Teks
Marsh, William M., author
Cambridge University Press, 2013
Buku Teks