E. Rama, and K. Sambaiah. “Solution of One Dimensional Wave Equation and Wave-Like Equations With Variable Coefficients Using Variational Iteration Method”. Malaya Journal of Matematik 9, no. 01 (January 1, 2021): 902–904. Accessed July 16, 2024. https://www.malayajournal.org/index.php/mjm/article/view/1187.