TY  - JOUR
AU  - T. A. Grigoryan
AU  - E. V. Lipacheva
AU  - V. H. Tepoyan
TI  - On $\pi$-extensions of the semigroup $\mathbb{Z}_+$
JO  - Proceedings of the Yerevan State University. Physical and mathematical sciences
PY  - 2013
SP  - 3
EP  - 5
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/UZERU_2013_1_a0/
LA  - en
ID  - UZERU_2013_1_a0
ER  -