Pages 3-4 in Lucinda Crile, Review of Extension Studies - January to June 1950, Extension Service Circular 470, U.S. Department of Agriculture, Washington, D.C. July 1950. Summary of findings from a M.S. thesis, University of Wisconsin, Madison. 1949. 123 pages., Effective use of the "various media and tools of communication..., perhaps, is the area of our present training program that needs most strengthening."