TY  - JOUR
AU  - Yu. V. Churin
TI  - Necessary and sufficient conditions for the existence of singular periodic solutions
JO  - Differencialʹnye uravneniâ
PY  - 1997
SP  - 714
EP  - 715
VL  - 33
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1997_33_5_a25/
LA  - ru
ID  - DE_1997_33_5_a25
ER  -