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Kenneth J. Sytsma, Jeffery Morawetz, J. Chris Pires, Molly Nepokroeff, Elena Conti, Michelle Zjhra, Jocelyn C. Hall & Mark W. Chase: Urticalean rosids: circumscription, rosid ancestry, and phylogenetics based on rbcL, trnL-F, and ndhF sequences., en American Journal of Botany, 2002, 89, S. 1531-1546: Online.Archivado el 6 de julio de 2008 en Wayback Machine.