Al-Hawasy, J. A. A. ., and N. F. . Mansour. “The Galerkin-Implicit Method for Solving Nonlinear Variable Coefficients Hyperbolic Boundary Value Problem”. Iraqi Journal of Science, vol. 62, no. 11, Nov. 2021, pp. 3997-05, doi:10.24996/ijs.2021.62.11.20.