TY  - JOUR
AU  - Porter, Jack R.
TI  - Extension Function and Subcategories of Haus
JO  - Canadian mathematical bulletin
PY  - 1975
SP  - 587
EP  - 590
VL  - 18
IS  - 4
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CMB-1975-103-x/
DO  - 10.4153/CMB-1975-103-x
ID  - 10_4153_CMB_1975_103_x
ER  -