Semalulu, O., M. K. Magunda, and D. N. Mubiru. “Use of Ca-Bentonite to Ameliorate Moisture and Nutrient Limitations of Sandy Soils in Drought Stricken Areas”. Uganda Journal of Agricultural Sciences, vol. 14, no. 2, Sept. 2013, pp. 49-59, http://journal.naro.go.ug/index.php/ujas/article/view/358.