TY  - JOUR
AU  - Bachir, A.
AU  - Segres, A.
TI  - On the  class operators.
JO  - International Journal of Open Problems in Computer Science and Mathematics. IJOPCM
PY  - 2009
SP  - 48
VL  - 2
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IJOPCM_2009__2_1_225649/
LA  - en
ID  - IJOPCM_2009__2_1_225649
ER  -