TY - JOUR AU - N. E. Tokmagambetov AU - B. T. Torebek TI - Symmetric differential operators of fractional order and their extensions JO - Trudy Moskovskogo matematičeskogo obŝestva PY - 2018 SP - 209 EP - 219 VL - 79 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/MMO_2018_79_2_a1/ LA - ru ID - MMO_2018_79_2_a1 ER -