Okpin, Fidelis Oko. “Integrating Urban Sustainability Education into the Curricula of Tertiary Institutions in Calabar Metropolis: Challenges and Opportunities”. Transdisciplinary Journal of Education & Sustainable Development Studies 1, no. 2 (September 4, 2025): 102–115. Accessed June 17, 2026. https://tjesds.org.ng/index.php/home/article/view/22.