TY  - JOUR
TI  - Openings in Mathematics
JO  - Canadian mathematical bulletin
PY  - 1964
SP  - 511
EP  - 512
VL  - 7
IS  - 3
UR  - http://geodesic.mathdoc.fr/articles/10.1017/S000843950003215X/
DO  - 10.1017/S000843950003215X
ID  - 10_1017_S000843950003215X
ER  -