TY  - JOUR
AU  - P.M. Higgins
TI  - Dense subsets of some common classes of semigroups.
JO  - Semigroup forum
PY  - 1986
SP  - 5
EP  - 20
VL  - 34
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1986__34_134827/
ID  - SF_1986__34_134827
ER  -