@Article{FrancisSteel2015,
AUTHOR = {Francis, Andrew R. and Steel, Mike},
TITLE = {Which phylogenetic networks are merely trees with additional arcs?},
YEAR = {2015},
JOURNAL = {Systematic Biology},
VOLUME = {64},
NUMBER = {5},
PAGES = {768-777},
URL = {http://dx.doi.org/10.1093/sysbio/syv037},
NOTE = {
http://arxiv.org/abs/1502.07045},
KEYWORDS = {explicit network, phylogenetic network, phylogeny, polynomial, tree-based network}
}