De Blij, Harm J.
John Wiley & Sons, 1996
Buku Referensi
Strahler, Alan H.
John Wiley & Sons, 1997
Buku Teks
Marsh, William M.
Cambridge University Press, 2013
Buku Teks
Strahler, Arthur N.
John Wiley & Sons, 1975
Buku Teks
Trewartha, Glenn T.
McGraw-Hill, 1967
Buku Teks