Alturky, S., and G. A. . TOMA. “A Hybrid Kharrat-Toma Transform With Homotopy Perturbation Method for Solving Integro-Differential Equations”. Journal of Mathematical Analysis and Modeling, vol. 2, no. 2, July 2021, pp. 50-62, doi:10.48185/jmam.v2i2.233.