Liu , ChunmeiShu , ShiHuang , YunqingZhong , Liuqiang and Wang , Junxian. (2012). An Iterative Two-Grid Method of a Finite Element PML Approximation for the Two Dimensional Maxwell Problem.
Advances in Applied Mathematics and Mechanics. 4 (2).
175-189.
doi:10.4208/aamm.10-m11166