TY  - JOUR
AU  - A. Wallace
TI  - Problems on semigroups
JO  - Colloquium Mathematicum
PY  - 1961
SP  - 223
EP  - 224
VL  - 8
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/cm-8-2-223-224/
DO  - 10.4064/cm-8-2-223-224
LA  - en
ID  - 10_4064_cm_8_2_223_224
ER  -