TY  - JOUR
AU  - P.G. Trotter
TI  - Congruence-free regular semigroups with zero.
JO  - Semigroup forum
PY  - 1976
SP  - 1
EP  - 5
VL  - 12
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1976__12_134151/
ID  - SF_1976__12_134151
ER  -