T.-H. Hubert Chan Kedar Dhamdhere Anupam Gupta Jon M. Kleinberg Aleksandrs Slivkins Metric Embeddings with Relaxed Guarantees. 2303-2329 2009 38 SIAM J. Comput. 6 http://dx.doi.org/10.1137/060670511 db/journals/siamcomp/siamcomp38.html#ChanDGKS09