Shalal, M., Jasim, K. and I.Al-Rijabo, W. 2008. Study of Reference Evapotranspiration in Ninava Governorate Using Different Mathematical Models. Rafidain Journal of Science. 19, 6 (Dec. 2008), 154–173. DOI:https://doi.org/10.33899/rjs.2008.41432.