TY - JOUR AU - V. I. Arnol'd TI - Singularities in the calculus of variations JO - Itogi Nauki i Tekhniki. Seriya Sovremennye Problemy Matematiki. Noveishie Dostizheniya PY - 1983 SP - 3 EP - 55 VL - 22 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/INTD_1983_22_a0/ LA - ru ID - INTD_1983_22_a0 ER -