1. Aich, V., B kone, F. F. Hattermann, and E. N. Muller. 2014. floods in the Niger basin-analysis and attribution. Natural Hazard and Earth System Sciences. 2: 5171-5212.
2. Issak, H.E., and, R.M. Srinivasta. 1989. applied geostatistics, oxford university Press: Oxford. 561p.
3. Jiang, T., B. Su, and H. Hartmann. 2007. temporal and spatial of precipitation and river flow in the Yangtze River Basin, 1961-2000. Geomorphology, 85: 143-154.
4. Johnston, K.m M. VerHoef, J., K. Krivoruchko, and L. Lucas. 2004. Arc GIS 9: Using Arc GIS Geostatistical Analyst. ESRI, 300p.
5. Karpouzos, D. K., S. Kavalieratou, and C, Babajimopoulos. 2010. Non parametric trend analysis of precipitation data in Pireia region (Greece), European water, 30: 31-40.