L. N. M. Tawfiq and R. W. Hussein, “On Solution of Regular Singular Initial Value Problems”, IHJPAS, vol. 26, no. 2, pp. 257–264, Apr. 2017, Accessed: Nov. 24, 2024. [Online]. Available: https://jih.uobaghdad.edu.iq/index.php/j/article/view/474