TY - JOUR AU - R. G. Dymanov TI - Singular points for three-dimensional systems of total differential equations in four-dimensional space JO - Differencialʹnye uravneniâ PY - 1968 SP - 283 EP - 289 VL - 4 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DE_1968_4_2_a10/ LA - ru ID - DE_1968_4_2_a10 ER -