E.I, N.; F.E, A. Estimation of Clear Sky Normal Irradiance Over Northern Nigeria Atmosphere. Research Journal of Ecology and Environmental Sciences, [S. l.], v. 1, n. 2, p. 96–107, 2021. Disponível em: https://www.scipublications.com/journal/index.php/rjees/article/view/123. Acesso em: 9 jul. 2025.