TY  - JOUR
AU  - N. I. Kovantsov
TI  - A ruled surface geometry analogue to a triorthogonal system of surfaces
JO  - Doklady Akademii Nauk
PY  - 1957
SP  - 497
EP  - 500
VL  - 113
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1957_113_3_a3/
LA  - ru
ID  - DAN_1957_113_3_a3
ER  -