@article{v007a005,
 author = {Robert Krauthgamer and Tim Roughgarden},
 title = {Metric Clustering via Consistent Labeling},
 year = {2011},
 pages = {49-74},
 doi = {10.4086/toc.2011.v007a005},
 publisher = {Theory of Computing},
 journal = {Theory of Computing},
 volume = {7},
 number = {1},
 URL = {http://www.theoryofcomputing.org/articles/v007a005},
}