TY  - JOUR
AU  - Brainerd, Barron
TI  - On Birkhoff's Problem 73 For Monoids
JO  - Canadian mathematical bulletin
PY  - 1960
SP  - 217
EP  - 220
VL  - 3
IS  - 3
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-1960-026-3/
DO  - 10.4153/CMB-1960-026-3
ID  - 10_4153_CMB_1960_026_3
ER  -