Khamare, Y., S. C. Marble, S. T. Steed, and N. S. Boyd. “Biology and Management of Spanish Needles (Bidens spp.) in Ornamental Crop Production: ENH-1308/EP572, 4/2019”. EDIS, vol. 2019, no. 2, Apr. 2019, p. 6, doi:10.32473/edis-ep572-2019.