Hao Gang Wang Chi Hou Chan Leung Tsang A new multilevel Green's function interpolation method for large-scale low-frequency EM simulations. 1427-1443 2005 24 IEEE Trans. on CAD of Integrated Circuits and Systems 9 http://dx.doi.org/10.1109/TCAD.2005.850804 db/journals/tcad/tcad24.html#WangCT05