Zydrunas Gimbutas and Leslie Greengard. (2018). Computational Software: Simple FMM Libraries for Electrostatics, Slow Viscous Flow, and Frequency-Domain Wave Propagation.
            <i>Communications in Computational Physics</i>. <i>18</i> (2).
            516-528.
         doi:10.4208/cicp.150215.260615sw