1. Allen, R.G., Pereira, L.S., Raes, D., Smith, M., (1998). Crop evapotranspiration, FAO Irrigation and Drainage Paper 56. Food and Agriculture Organization, Rome.
2. Abramowitz, M., Stegun, I.A., (1965). Handbook of mathematical functions: with formulas, graphs, and mathematical tables. Applied Mathematics Series - 55, Washington D.C.
3. AsadiZarch, M.A., Malekinezhad, H., Hossein, M., Dastorani, M.T., Kousari, M., (2010). Drought Monitoring by Reconnaissance Drought Index (RDI) in Iran. Water Resour Manage, DOI 10.1007/s11269-011-9867-1.
4. CRDE, (2003). The Centre for Research on the Epidemiology of Disasters. Disasters Database. http://www. cred.be/emdat/intro.htm. UniversiteCatholique de Louvain, Brussels- Belgium.
5. Doorenbos, J., Kassam, A.H., (1986). Yield response to water. Yield response to water, Irrigation and Drainage Paper 33. Food and Agriculture Organization, Rome.
6. Doorenbos, J., Pruitt, O.W., (1977). Crop water requirements. FAO Irrigation and Drainage Paper 24. Food and Agriculture Organization, Rome.
7. Fischer, G., Van Velthuizen, H., Nachtergaele. (2000). Global agro-ecological zones assessment. International Institute for Applied Systems Analysis, Laxenburg.
8. Gibbs, W.J., Maher, J.V., (1967). Rainfall deciles as drought indicators. Bureau of Meteorology Bulletin 48. Commonwealth of Australia, Melbourne.
9. Guttmann, N.B., (1998). Comparing the Palmer drought index and the standardized precipitation index. J Am Water ResourAssoc. 34:113-121.
10. Hayes, M.J., (2000). Revisiting the SPI: clarifying the process. Drought Network News, A Newsletter of the International Drought Information Center and the National Drought Mitigation Center 12(1,Winter 1999–Spring 2000):13-15.
11. Jensen, M.E., Burman, R.D., Allen, R.G., (1990). Evaporation and irrigation water requirements. ASCE Manuals and Reports on Engineering Practices, New York.
12. McKee, T.B., Doeskin, N.J., Kleist, J., (1995). Drought monitoring with multiple time scales, January 15–20, 1995. American Meteorological Society, Proceeding of the 9th Conference on Applied Climatology, Boston: 233-236.
13. McKee, T.B., Doeskin, N.J., Kleist, J., (1993). The relationship of drought frequency and duration to time scales. In Proceedings of the 8th Conference on Applied Climatology, Anaheim, CA, January 17–23, 1993. American Meteorological Society. Boston, MA: 179-184.
14. Mendicino, G., Senatore, A., Versace, P., (2008). A Groundwater Resource Index (GRI) for drought monitoring and forecasting in a Mediterranean climate. J Hydrol., 357:282-302.
15. Mishra, A.K., Desai, V.R., (2005). Drought forecasting using stochastic models. Stochast Environ Res Risk Assess, 19:326-339.
16. Monteith, J.L., (1965). Evaporation and the environment. The state and movement of water in living organisms. Cambridge University Press, Swansea: 205-234.
17. Nicholson, S.E., Davenport, M.L., Malo, A.R., (1990). A comparison of the vegetation response to rainfall in the Sahel and east Africa, using normalized difference vegetation index from NOAA-AVHRR. Clim Change, 17(2-3):209-241.
18. Obasi, G.O.P., (1994). WMO’s role in the international decade for natural disaster reduction. Bull Amer Meteor Soc., 75:1655-1661.
19. Pickup, G., (1998). Desertification and climate change—the Australian perspective. Clim Res 11:51-63.
20. Rossi, G., (2000). Drought mitigation measures: a comprehensive framework. In: Voght JV, Somma F (eds) Drought and drought mitigation in Europe. Kluwer, Dordrecht.
21. Sönmez, F.K., Kömüscü, A.Ü., Erkan, A., Turgu, E., (2005). An analysis of spatial and temporal dimension of drought vulnerability in Turkey using the standardized precipitation index. Nat Hazards, 35:243-264.
22. Smith, M., (1992). Expert consultation on revision of FAO methodologies for crop water requirements. Land and Water Development Division, Food and Agriculture Organization, Rome.
23. Tsakiris, G., Pangalou, D., Vangelis, H., (2007), Regional drought assessment based on the Reconnaissance Drought Index (RDI). Water ResourManag, 21(5):821-833.
24. Tsakiris, G., Rossi, G., Iglesias, A., Tsiourtis, N., Garrote, L., Cancelliere, A., (2006). Drought Indicators Report. Report made for the needs of the European Research Program MEDROPLAN (Mediterranean Drought Preparedness and Mitigation Planning).
25. Tsakiris, G., Vangelis, H., (2005). Establishing a drought index incorporating evapotranspiration. Eur Water, 9(10):1-9.
26. Tsakiris, G., (2004). Meteorological Drought Assessment. Paper prepared for the needs of the European Research Program MEDROPLAN (Mediterranean Drought Preparedness and Mitigation Planning), Zaragoza, and Spain.
27. Tsakiris, G., Nalbantis, I., Pangalou, D., Tigkas, D., Vangelis, H., (2008). Drought meteorological monitoring network design for the Reconnaissance Drought Index (RDI), 1st International Conference “Drought Management: Scientific and Technological Innovations”, Zaragoza – Spain.
28. UNEP, (1992). World Atlas of desertification. Edward Arnold, London.
29. UNESCO, (1979). Map of the world distribution of arid regions. Explanatory note. Man and Biosphere (MAB).
30. Wilhite, D.A., Hayes, M.J., Svodoba, M.D., (2000). Drought monitoring and assessment in the U.S. In: Voght JV, Somma F (eds) Drought and drought mitigation in Europe. Kluwers, Dordrecht.
31. Wilhite, D., (2000). Drought preparedness in the U.S. In: Vogt JV, Somma F (eds) Drought and drought mitigation in Europe. Kluwer, the Netherlands.119-132.