Khan, B., A. . Sohail, T. A. . Faridi, U. . Jan, F. . Zahid, and I. . Parveen. “Relation Between Different Grades of Pterygium and Amount of Induced Corneal Astigmatism: Different Grades of Pterygium”. Pakistan BioMedical Journal, vol. 4, no. 2, Oct. 2021, pp. 59-63, doi:10.54393/pbmj.v4i2.74.