Tang, E. N. ., and F. A. . Ngome. “The Integrated Effects of Fertilizer on Sweet Potato (Ipomea Batatas, Lam.) in Andosol and Nitisol Soils”. International Journal of Sustainable Agricultural Research, vol. 9, no. 1, Apr. 2022, pp. 28-45, doi:10.18488/ijsar.v9i1.2962.