Akpalu, S. E., G. K. Adeyiga, M. K. Amooh, D. Kyereh, and M. M. Akpalu. “Population Density and Diversity of Trees on Farmlands in Three Districts of the Upper East Region of Ghana: Implications for Food Security and Ecosystem Sustainability”. New Perspectives in Agriculture and Crop Science Vol. 1, Oct. 2019, pp. 119-31, https://stm1.bookpi.org/index.php/npacs-v1/article/view/573.