TY - JOUR AU - A. A. Zlotnik AU - I. D. Turetaev TI - Sharp error estimates of some two-level methods of solving the three-dimensional heat equation JO - Sbornik. Mathematics PY - 1987 SP - 529 EP - 544 VL - 56 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/SM_1987_56_2_a14/ LA - en ID - SM_1987_56_2_a14 ER -