Richard Nock Panu Luosto Jyrki Kivinen Mixed Bregman Clustering with Approximation Guarantees. 154-169 2008 ECML/PKDD (2) http://dx.doi.org/10.1007/978-3-540-87481-2_11 conf/pkdd/2008-2 db/conf/pkdd/pkdd2008-2.html#NockLK08