TY - JOUR AU - M. A. Abel TI - Scientific Conference “Methods of Algebra and Logic” JO - Trudy Matematicheskogo Instituta imeni V.A. Steklova PY - 1989 VL - 44 IS - 3 UR - http://geodesic.mathdoc.fr/item/RM_1989_44_3_a30/ LA - ru ID - RM_1989_44_3_a30 ER -