Verbatim text: Dennis, W. M. and D. H. Webb. 1981. The distribution of Pilularia americana A. Br. (Marsileaceae) in North America, north of Mexico. Sida 9: 19--24. Petrik-
Author: Dennis, W.M., Webb, D.H.
Year: 1981
Title: The distribution of Pilularia americana A. Br. (Marsileaceae) in North America, north of Mexico
Journal: Sida
Volume: 9
Pages: 19–24