F. O. Adekayode, and D. T. Akomolafe. “Creating a Soil Data Base in a Reconnaissance Soil Fertility Study of an Encroached Forest Reserve in Northern Nigeria for a Reforestation Programme”. African Journal of Environmental Economics and Management, vol. 7, no. 1, May 2019, pp. 490-6, https://elixirpublishers.in/index.php/ajeem/article/view/1061.