Indranil Chowdhury Vikram Jandhyala Multilevel multipole and local operators for potentials of the form <i>r</i><sup>-<i>lambda</i></sup>. 1184-1189 2005 18 Appl. Math. Lett. 10 http://dx.doi.org/10.1016/j.aml.2005.02.007 db/journals/appml/appml18.html#ChowdhuryJ05