Verbatim text: Jackson, S. W. 1963. Hybridization among three species of Ratibida. Univ. Kansas Sci. Bull. 44: 3–27.
Author: Jackson, S.W.
Year: 1963
Title: Hybridization among three species of Ratibida
Journal: Univ. Kansas Sci. Bull
Volume: 44
Pages: 3–27