Verbatim text: Sarvela, J., D. M. Britton, and K. M. Pryer. 1981. Studies on the Gymnocarpium robertianum complex in North America. Rhodora 83: 421--431.
Author: Sarvela, J., Britton, D.M., Pryer, K.M.
Year: 1981
Title: Studies on the Gymnocarpium robertianum complex in North America
Journal: Rhodora
Volume: 83
Pages: 421–431