@misc{10_1017_S000843950002703X, title = {Journal of {Applied} {Probability}}, journal = {Canadian mathematical bulletin}, pages = {171--171}, year = {1964}, volume = {7}, number = {1}, doi = {10.1017/S000843950002703X}, url = {http://geodesic.mathdoc.fr/articles/10.1017/S000843950002703X/} }