Shahzad, Rasim, et al. “Wavelet Analysis Based VTEC Variability over Mid-Latitude Region Sukkur, Pakistan and Its Comparison With IRI Models During 2019-2020”. Natural and Applied Sciences International Journal (NASIJ), vol. 3, no. 1, June 2022, pp. 13-33, doi:10.47264/idea.nasij/3.1.2.