TY  - JOUR
AU  - B. Piochi
TI  - Permutability of normal extensions of a semilattice.
JO  - Semigroup forum
PY  - 1991
SP  - 151
EP  - 162
VL  - 43
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1991__43_3_135105/
ID  - SF_1991__43_3_135105
ER  -