PRAMANIK, S. K., and S. YEGNA NARAYANAN. “Diurnal Magnetic Variation in Equatorial Regions”. MAUSAM 3, no. 3 (July 1, 1952): 212–216. Accessed February 12, 2025. https://mausamjournal.imd.gov.in/index.php/MAUSAM/article/view/4753.