TY  - JOUR
AU  - J. Almeida
TI  - On the membership problem for pseudo-varieties of commutative semigroups.
JO  - Semigroup forum
PY  - 1991
SP  - 47
EP  - 52
VL  - 42
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1991__42_3_135062/
ID  - SF_1991__42_3_135062
ER  -