The article appeared in the journal PLOS ONE on October 30.
URI:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0141882
Citation:
Dupuis JR, Sperling FAH (2015) Repeated Reticulate Evolution in North American Papilio machaon Group Swallowtail Butterflies. PLoS ONE 10(10): e0141882. doi:10.1371/journal.pone.0141882