Vakarchuk, M. B., and S. B. Vakarchuk. “On the Exponential Decay of Vibrations of Damped Elastic Media”. Ukrains’kyi Matematychnyi Zhurnal 63, no. 12 (December 25, 2011): 1579-1601. Accessed April 26, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2828.