Miquel Ferrer Dimosthenis Karatzas Ernest Valveny Horst Bunke A Recursive Embedding Approach to Median Graph Computation. 113-123 2009 GbRPR http://dx.doi.org/10.1007/978-3-642-02124-4_12 conf/gbrpr/2009 db/conf/gbrpr/gbrpr2009.html#FerrerKVB09