TY  - JOUR
AU  - A. A. Davydov
TI  - Singularities of fields of limiting directios of two-dimensional control systems
JO  - Sbornik. Mathematics
PY  - 1989
SP  - 471
EP  - 493
VL  - 64
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SM_1989_64_2_a12/
LA  - en
ID  - SM_1989_64_2_a12
ER  -