Tartaglia, E. S., and S. N. Handel. “Nectar Plant Preferences of Hemaris (Sphingidae) on Co-Occurring Native Cirsium and Non-Native Centaurea (Asteraceae) Inflorescences”. Journal of Pollination Ecology, vol. 13, June 2014, pp. 184-7, doi:10.26786/1920-7603(2014)16.