USA: Extension Service, U.S. Department of Agriculture, Washington, D.C.
Location:
Agricultural Communications Documentation Center, Funk Library, University of Illinois Document Number: D08957
Notes:
Page 16 in Lucinda Crile, Findings from studies of bulletins, news stories, and circular letters. Extension Service Circular 488. Revision of Extension Service Circular 461, which it supersedes. May 1953. 24 pages. Summary of research reported by the National Fertilizer Association, Inc., Washington, D.C. 1929. 38 pages.
