Islam, M. Z. “An Asymptotic Method for Periodic Solution of Nonlinear Autonomous Systems Modeled by Second Order Hyperbolic Type Partial Differential Equation”. Rajshahi University Journal of Science and Engineering 53 (August 13, 2026): 1–9. Accessed August 15, 2026. https://journal.ru.ac.bd/rujse/article/view/206.