Jakub Koperwas Krzysztof Walczak 0002 Frequent Subsplit Representation of Leaf-Labelled Trees. 95-105 2008 EvoBIO http://dx.doi.org/10.1007/978-3-540-78757-0_9 conf/evoW/2008bio db/conf/evoW/evobio2008.html#KoperwasW08