Gabriel Cardona Mercè Llabrés Francesc Rosselló Gabriel Valiente Metrics for Phylogenetic Networks I: Generalizations of the Robinson-Foulds Metric. 46-61 2009 6 IEEE/ACM Trans. Comput. Biology Bioinform. 1 http://doi.acm.org/10.1145/1512443.1512455 db/journals/tcbb/tcbb6.html#CardonaLRV09