TY  - JOUR
AU  - D. O. Ptakhov
TI  - Primitive normality and additivity of free projective and strongly flat polygons
JO  - Algebra i logika
PY  - 2014
SP  - 614
EP  - 624
VL  - 53
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/AL_2014_53_5_a3/
LA  - ru
ID  - AL_2014_53_5_a3
ER  -