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2. GIS-based hydrological zones and soil geo-database of Ethiopia
3. Methods of Soil Analysis
4. Central Statistics Agency (CSA). 2021. Agriculture sample survey 2020/2021: Volume I. Report on area and production of major crops (private peasant holdings meher season) Statistical Bulletin 590. Addis Ababa Ethiopia: The Federal Democratic Republic of Ethiopia Central Statistical Agency.
5. Cation-Exchange Capacity