Verbatim text: Ruffin, J. 1974. A taxonomic evaluation of the genera Amphiachyris, Amphipappus, Greenella, Gutierrezia, Gymnosperma, Thurovia, and Xanthocephalum (Compositae). Sida 5: 301–333.
Author: Ruffin, J.
Year: 1974
Title: A taxonomic evaluation of the genera Amphiachyris, Amphipappus, Greenella, Gutierrezia, Gymnosperma, Thurovia, and Xanthocephalum (Compositae)
Journal: Sida
Volume: 5
Pages: 301–333