P. Saroj and S. Sahu, “Reflection of Plane Wave at Traction-Free Surface of a Pre-Stressed Functionally Graded Piezoelectric Material (FGPM) Half-Space”, J. Solid Mech., vol. 9, no. 2, pp. 411–422, Jun. 2017, Accessed: Jun. 06, 2026. [Online]. Available: https://oiccpress.com/jsm/article/view/12605