TY - JOUR T1 - Accelerating the multilevel fast multipole algorithm with the sparse-approximate-inverse (SAI) preconditioning A1 - Malas, T. A1 - Gurel, L. JA - SIAM J on Scientific Computing Y1 - 2009 VL - 31 SP - 1968 EP - 1984 N1 - upd vol/pg 07-04-09 ER -