Reference [1] L. Greengard and V. Rokhlin, J. Comput. Phys., vol. 73, pp. 325-348, 1987. [2] N. A. Gumerov and R. Duraiswami, J. Comput. Phys., vol. 227, pp. 8290-8313, 2008. [3] A. Boag and E. Michielssen, A. Brandt, IEEE Antennas and Wireless Propagation Letters, vol. 1, pp.142-145, 2002 [4] A. Boag and B. Livshitz, IEEE Trans. on MTT, vol. 54, pp. 3365-3570, 2006. [5] A. Boag, V. Lomakin, an...