Reference:Steere1939b
Verbatim text: Steere, W. C. 1939b. Barbula in North America north of Mexico. Bull. Torrey Bot. Club 66: 93–119.
Author: Steere, W.C.
Year: 1939b
Title: Barbula in North America north of Mexico
Journal: Bull. Torrey Bot. Club
Volume: 66
Pages: 93–119
PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/2480994