Umoh, Mfon David, Sunday O Udo, and Ye-Obong N Udoakah. “Estimation of Global Solar Radiation on Horizontal Surface from Sunshine Hours and Other Meteorological Parameters for Calabar, Nigeria”. Journal of Asian Scientific Research 3, no. 11 (November 15, 2013): 1083–1089. Accessed November 22, 2024. https://archive.aessweb.com/index.php/5003/article/view/3566.