Verbatim text: Carlson, T. J. and W. H. Wagner Jr. 1982. The North American distribution of the genus Dryopteris. Contr. Univ. Michigan Herb. 15: 141--162.
Author: Carlson, T.J., Wagner, W.H. Jr.
Year: 1982
Title: The North American distribution of the genus Dryopteris
Journal: Contr. Univ. Michigan Herb
Volume: 15
Pages: 141–162