Simon, J.E., A.F. Chadwick and L.E. Craker. 1984. Herbs: An Indexed Bibliography. 19711980.
Handbook of Energy CropsJames A. Duke. 1983. unpublished
Sievers, A.F. 1930. The Herb Hunters Guide. Misc. Publ. No. 77. USDA, Washington DC.
Comfrey: Alternative Field Crops Manual, University of Wisconson Cooperative Extension Service, University of Minnesota Extension Service, Center for Alternative Plant & Animal Products
Copyright © 2013, Purdue University, all rights reserved. Purdue University is an equal access/equal opportunity university. If you have trouble accessing this page because of a disability, please contact the NewCROP Center | email: firstname.lastname@example.org | phone: 765-494-6968.
Last modified: June 12 2014 by aw