1. Physiographic diagram of the United States;Lobeck,1957
2. General introduction and hydrologic definitions;Langbein;U. S. Geol. Survey Water Supply Paper 1541-A,1960
3. An approach toward a rational classification of climate;Thornthwaite;Geograph. Rev.,1948
4. Methods of computing consumptive use of water;Criddle,1958
5. Irrigation and climate;Henry Olivier,1964