@misc{ elkan03using,
author = "C. Elkan",
title = "Using the triangle inequality to accelerate kMeans",
text = "C. Elkan. Using the triangle inequality to accelerate kMeans. In Proceedings
of the Twentieth International Conference on Machine Learning, 2003, pp.
147-153.",
year = "2003",
url = "citeseer.ist.psu.edu/elkan03using.html"
}