TY  - JOUR
AU  - Ya. N. Fel'd
TI  - A criterion for the realizability of direction diagrams by
JO  - Doklady Akademii Nauk
PY  - 1988
SP  - 583
EP  - 587
VL  - 300
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1988_300_3_a15/
LA  - ru
ID  - DAN_1988_300_3_a15
ER  -