TY  - JOUR
AU  - V. V. Vedyushkina
TI  - Orbital invariants of flat billiards bounded by arcs of confocal quadrics and containing focuses
JO  - Vestnik Moskovskogo universiteta. Matematika, mehanika
PY  - 2021
SP  - 48
EP  - 51
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/VMUMM_2021_4_a8/
LA  - ru
ID  - VMUMM_2021_4_a8
ER  -