TY - JOUR TI - Problems for Solution JO - Canadian mathematical bulletin PY - 1972 SP - 149 EP - 154 VL - 15 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.1017/S0008439500031295/ DO - 10.1017/S0008439500031295 ID - 10_1017_S0008439500031295 ER -