Esang, D. M., and A. O. Ikeh. “Response of Some Improved Upland Rice Varieties to Different Sources and Rates of Nitrogen Fertilizer in A Humid Rain Forest Region”. American Journal of Agricultural Science, Engineering, and Technology, vol. 5, no. 2, Sept. 2021, pp. 69-91, doi:10.54536/ajaset.v5i2.75.