J. MacQueen. Proceedings of the 5th Berkeley Symposium on Mathematical Statistics and Probability - Vol. 1, page 281--297. University of California Press, Berkeley, CA, USA, (1967)
J. MacQueen. Proceedings of the 5th Berkeley Symposium on Mathematical Statistics and Probability - Vol. 1, page 281--297. University of California Press, Berkeley, CA, USA, (1967)