Yakubu, M., and A. Ojanuga. “Pedogenesis, Weathering Status and Mineralogy of the Soils on Ironstone Plateaux (laterites), Sokoto Nigeria”. Bayero Journal of Pure and Applied Sciences, vol. 6, no. 2, Jan. 2014, pp. 93-100, doi:10.4314/bajopas.v6i2.19.