Kevin Buchin Maike Buchin Marc J. van Kreveld Maarten Löffler Jun Luo Rodrigo I. Silveira Clusters in Aggregated Health Data. 77-90 2008 SDH http://dx.doi.org/10.1007/978-3-540-68566-1_5 conf/sdh/2008 db/conf/sdh/sdh2008.html#BuchinBKLLS08