TY - JOUR AU - S. I. Trifonov TI - Analytic families of differential equations on two-dimensional JO - Doklady Akademii Nauk PY - 1993 SP - 559 EP - 562 VL - 331 IS - 5 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DAN_1993_331_5_a8/ LA - ru ID - DAN_1993_331_5_a8 ER -