TY  - JOUR
AU  - Amha Tume Lisan
TI  - Free groups in ßN which miss the minimal ideal.
JO  - Semigroup forum
PY  - 1988
SP  - 233
EP  - 240
VL  - 37
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/SF_1988__37_1_134927/
ID  - SF_1988__37_1_134927
ER  -