TY - JOUR AU - F. Z. Ziatdinov TI - Linear differential operators of second order in a~Hilbert space of vector functions with values in an abstract separable Hilbert space JO - Izvestiâ vysših učebnyh zavedenij. Matematika PY - 1960 SP - 89 EP - 100 IS - 4 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/IVM_1960_4_a9/ LA - ru ID - IVM_1960_4_a9 ER -