TY  - JOUR
AU  - J.B. Kirn
TI  - No semigroup is a finite union of mutants.
JO  - Semigroup forum
PY  - 1974
SP  - 360
EP  - 361
VL  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1974__6_133995/
LA  - en
ID  - SF_1974__6_133995
ER  -