TY - JOUR AU - N. B. Medvedeva TI - On the Analytic Solvability of the Problem of Distinguishing between Center and Focus JO - Informatics and Automation PY - 2006 SP - 11 EP - 100 VL - 254 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TRSPY_2006_254_a1/ LA - ru ID - TRSPY_2006_254_a1 ER -