“Diurnal and Seasonal Variation of Surface Refractivity in Minna and Lapai, North Central Nigeria”. International Journal of Engineering Research and Advanced Technology (ijerat) (E-ISSN 2454-6135) 4, no. 7 (July 5, 2018): 16–24. Accessed July 27, 2024. https://ijerat.com/index.php/ijerat/article/view/387.