TY  - JOUR
AU  - G. I. Trushin
TI  - Third order conjugate systems and the problem of their focal transformations
JO  - Doklady Akademii Nauk
PY  - 1960
SP  - 265
EP  - 268
VL  - 131
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1960_131_2_a12/
LA  - ru
ID  - DAN_1960_131_2_a12
ER  -