TY - JOUR AU - Elias A. Lipitakis AU - George A. Gravvanis TI - The Convergence rate and Complexity of Precondotioned Iterative methods based on Approximate finite Element matrix Factorization JO - Μαθηματική Επιθεώρηση PY - 1987 SP - 11 EP - 23 VL - 33 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MR_1987__33_a1/ LA - gr ID - MR_1987__33_a1 ER -