1. American Meteorological Society: 2003, Meteorological drought, Bull. Am. Met. Soc.85, USA.
2. North Atlantic influence on Tigris-Euphrates streamflow
3. On the definition of droughts
4. Downing, T. E. and Bakker, K.: 2000, Drought discourse and vulnerability, In: D. A. Wilhite (ed), Drought: A Global Assessment,Natural Hazards and Disasters Series, Routledge Publishers, UK.