Funk, Vicki A.; Chan, Raymund; Keeley, Sterling C. (2004). "Insights into the Evolution of the Tribe Arctoteae (Compositae: Subfamily Cichorioideae s.s.) Using trnL-F, ndhF, and ITS". Taxon. 53 (3): 637–655. doi:10.2307/4135440. JSTOR4135440.
Funk, Vicki A.; Chan, Raymund; Keeley, Sterling C. (2004). "Insights into the Evolution of the Tribe Arctoteae (Compositae: Subfamily Cichorioideae s.s.) Using trnL-F, ndhF, and ITS". Taxon. 53 (3): 637–655. doi:10.2307/4135440. JSTOR4135440.