Ryding, Olof; Bremer, Kare (1992), "Phylogeny, Distribution, and Classification of the Coreopsideae (Asteraceae)", Systematic Botany, 17 (4): 649–659, doi:10.2307/2419733, JSTOR2419733
Ryding, Olof; Bremer, Kare (1992), "Phylogeny, Distribution, and Classification of the Coreopsideae (Asteraceae)", Systematic Botany, 17 (4): 649–659, doi:10.2307/2419733, JSTOR2419733