Verbatim text: Sell, P. D. and P. F. Yeo. 1970. A revision of the North American species of Euphrasia L. (Scrophulariaceae). Bot. J. Linn. Soc. 63: 189–234.
Author: Sell, P.D., Yeo, P.F.
Year: 1970
Title: A revision of the North American species of Euphrasia L. (Scrophulariaceae)
Journal: Bot. J. Linn. Soc
Volume: 63
Pages: 189–234