TY  - JOUR
AU  - Michael Barr
TI  - Note on a  theorem of Putnam's
JO  - Theory and applications of categories
PY  - 1997
SP  - .45
EP  - 49
http://www
VL  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/TAC_1997_3_a2/
LA  - en
ID  - TAC_1997_3_a2
ER  -