Chatterjee, S., and P. K. Purohit. “Effect of Ionospheric Perturbation on GPS Observation over Low Latitude Region, Bhopal”. Journal of Scientific Research 4, no. 3 (August 28, 2012): 577–587. Accessed August 17, 2024. https://banglajol.info/index.php/JSR/article/view/10146.