On the dynamic behavior of a functionally graded viscoelastic-piezoelectric composite substrate subjected to a moving line loadAbhishek Kumar Singh, Siddhartha Koley, Anil Negi and Anusree RayEur. Phys. J. Plus, 134 3 (2019) 95DOI: https://doi.org/10.1140/epjp/i2019-12444-2