altaher, ahsan, & Hameeda Oda Al-Humedi. (2020). A Combination of the Orthogonal Polynomials with Least – Squares Method for Solving High-Orders Fredholm-Volterra Integro-Differential Equations. Al-Qadisiyah Journal of Pure Science, 26(1), Math 20-38. https://doi.org/10.29350/qjps.2021.26.1.1207