M. F. Hadi, “A Finite Volumes-Based 3-D Low Dispersion FDTD Algorithm ", IEEE Transactions on Antennas and Propagation, Volume: 55  Issue: 8, Aug. 2007, Page(s): 2287-2293

The publication is available to download from http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=4285964&isYear=2007