TY  - JOUR
AU  - R. I. Khrapko
TI  - Defining the space type on Petrov's classification
JO  - Doklady Akademii Nauk
PY  - 1967
SP  - 56
EP  - 57
VL  - 176
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1967_176_1_a13/
LA  - ru
ID  - DAN_1967_176_1_a13
ER  -