Jan Steffen Stefan Klanke Sethu Vijayakumar Helge Ritter Towards Semi-supervised Manifold Learning: UKR with Structural Hints. 298-306 2009 WSOM http://dx.doi.org/10.1007/978-3-642-02397-2_34 conf/wsom/2009 db/conf/wsom/wsom2009.html#SteffenKVR09