Ogbologwung , L., O. . D.A., and A. O. M. “Effect of Spent Mushroom Substrate and NPK Fertilizer on White and Orange-Fleshed Sweet Potato Varieties in South Eastern Nigeria”. Uganda Journal of Agricultural Sciences, vol. 21, no. 2, Sept. 2021, pp. 31-40, https://journal.naro.go.ug/index.php/ujas/article/view/486.