Eissa, R. P., and M. M. Gad. “CUBIC MECHANICAL METHOD FOR THE NONLINEAR SYSTEM OF SINGULAR INTEGRAL EQUATIONS”. Tamkang Journal of Mathematics 21, no. 3 (September 1, 1990): 201–209. Accessed April 23, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4659.