Verbatim text: Zimmerman, W. J., T. A. Lumpkin, and I. Watanabe. 1989. Classification of Azolla spp., section Azolla. Euphytica 43: 223--232.
Author: Zimmerman, W.J., Lumpkin, T.A., Watanabe, I.
Year: 1989
Title: Classification of Azolla spp., section Azolla
Journal: Euphytica
Volume: 43
Pages: 223–232