Rozycki, P., Moes, N., Bechet, E., & Dubois, C. (2008). X-FEM explicit dynamics for constant strain elements to alleviate mesh constraints on internal or external boundaries. Computer Methods in Applied Mechanics and Engineering, 197(5), 349-363. https://doi.org/10.1016/j.cma.2007.05.011 (Original work published 2008)