Abedi, R. ., R. B. Haber, S. . Thite, and J. . Erickson. “An H-Adaptive Spacetime-Discontinuous Galerkin Method for Linear Elastodynamics”. European Journal of Computational Mechanics, vol. 15, no. 6, June 2006, pp. 619-42, https://journals.riverpublishers.com/index.php/EJCM/article/view/2059.