Verbatim text: Pfeiffer, N. E. 1922. Monograph of the Isoëtaceae. Ann. Missouri Bot. Gard. 9: 79--233.
Author: Pfeiffer, N.E.
Year: 1922
Title: Monograph of the Isoëtaceae
Journal: Ann. Missouri Bot. Gard
Volume: 9
Pages: 79–233
PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/2990000
BHL link: http://www.biodiversitylibrary.org/part/9930