Page 79 in Extension Circular 532, Review of Extension Research, January through December 1959, U.S. Department of Agriculture, Washington, D.C. Summary of research report, College of Agriculture, University of Illinois, Urbana. 1959. 24 pages.
Pages 79-80 in Extension Circular 532, Review of Extension Research, January through December 1959, U.S. Department of Agriculture, Washington, D.C. Summary of research report, master of science in agricultural education, University of Minneapolis, St. Paul. 1959
Page 53 in Extension Service Circular 544, Review of Extension Research, January through December 1961, U.S. Department of Agriculture, Washington, D.C. Summary of Progress Report 120, Agricultural Experiment Station and Department of Rural Sociology, University of Kentucky, Lexington. 1962. 16 pages.
