References
Grieve, M. 1931.  A Modern Herbal, (ed. C.F. Leyel 1985), London.

http://www.purplesage.org.uk/profiles/pasqueflower.htm

Shirley, Shirley. 1994. Restoring the Tallgrass Prairie: An Illustrated
     Manual for Iowa and the Upper Midwest.  Iowa City: University
     Iowa Press.
 

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