TY  - JOUR
AU  - Shi Mingquan
TI  - Some Results of the π-Semigroups
JO  - Mathematica balkanica
PY  - 1991
SP  - 81
VL  - 5
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MABA_1991_5_2_a0/
ID  - MABA_1991_5_2_a0
ER  -