Mark Allan Wetter, Theodore S. Cochrane, Merel R. Black, Hugh H. Iltis & Paul E. Berry books & textbook
Checklist Of The Vascular Plants Of Wisconsin Technical Bulletin No. 192, 2001
Mark Allan Wetter, Theodore S. Cochrane, Merel R. Black, Hugh H. Iltis & Paul E. Berry
Wisconsin State Herbarium /2001T Paperback