Strahler, Arthur N., author
John Wiley & Sons, 1973
Buku Teks
Basil Gomez and John Paul Jones III, edited
Wiley-Blackwell, 2010
Buku Teks
Mackinnon, Danny, author
Pearson, Prentice Hall, 2007
Buku Teks
Newbigin, Marion I.
Dent & sons, Ltd., 1925
Buku Teks
Unwin, Tim, author
Longman Scientific & Technical, 1992
Buku Teks