Waila, Musa K. A., and Nuhu H. Tini. “Appraisal of the Extent of Environmental Education Among Students in Mubi Metropolis-Adamawa State-Nigeria”. Journal of Research in Education and Society (JRES) , vol. 2, no. 1, Apr. 2011, pp. 87-96, http://icidr.org.ng/index.php/Jres/article/view/1164.