Mian Dong, Anxue Zhang, Juan Chen, Songlin Zhang, and Yuchen He. “The Fourth-Order One-Step Leapfrog HIE-FDTD Method”. Applied Computational Electromagnetics Society Journal (ACES), vol. 31, no. 12, Aug. 2021, pp. 1370-6, https://journals.riverpublishers.com/index.php/ACES/article/view/9787.