TY  - JOUR
AU  - M. A. Akivis
TI  - Transformations of surfaces by means of focal families of rays
JO  - Trudy Matematicheskogo Instituta imeni V.A. Steklova
PY  - 1961
VL  - 16
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/RM_1961_16_1_a18/
LA  - ru
ID  - RM_1961_16_1_a18
ER  -