SRINIVASAN, P. K., and N. SIVASANKARA SASTRI. “Direction of Rapid Geomagnetic Changes at Indian Observatories”. MAUSAM 15, no. 1 (January 1, 1964): 90–94. Accessed September 20, 2024. http://103.215.208.102/index.php/MAUSAM/article/view/5524.