@misc{10_1017_S0008439500024905,
     title = {P 15.},
     journal = {Canadian mathematical bulletin},
     pages = {44--44},
     year = {1959},
     volume = {2},
     number = {1},
     doi = {10.1017/S0008439500024905},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0008439500024905/}
}