Verbatim text: Heckard, L. R. and L. T. Collins. 1982. Taxonomy and distribution of Orobanche valida (Orobanchaceae). Madroño 29: 95–100.
Author: Heckard, L.R., Collins, L.T.
Year: 1982
Title: Taxonomy and distribution of Orobanche valida (Orobanchaceae)
Journal: Madroño
Volume: 29
Pages: 95–100