Tarus, S. J. ., J. L. . Kituyi, and F. K. . Segor. “Spatial and Temporal Variability of Phosphates, Nitrates and Selected Physico-Chemical Parameters of River Nzoia”. Africa Environmental Review Journal, vol. 5, no. 2, Nov. 2022, pp. Pg 29-41, doi:10.2200/aerj.v5i2.249.