TY  - JOUR
AU  - W. Williams
AU  - I. Levi
TI  - Normal semigroups of partial one-to-one transformations II.
JO  - Semigroup forum
PY  - 1991
SP  - 344
EP  - 356
VL  - 43
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1991__43_3_135121/
ID  - SF_1991__43_3_135121
ER  -