Lobeck, A.K.
McGraw-Hill, 1939
Buku Teks
Bennison, George Mills, author
Routledge, 2013
Buku Teks
Strahler, Arthur N., author
John Wiley & Sons, 1967
Buku Teks
Strahler, Arthur N., author
John Wiley & Sons, 1973
Buku Teks
Newbigin, Marion I.
Dent & sons, Ltd., 1925
Buku Teks