Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
The Poultry Industry, since its products were designated as essential foods for the Defense Program by Secretary of Agriculture Wickard, has been expanding to meet the requests for increased production in April, 1941.
Wilke, H. L.
"Feeding for Hatchability,"
Iowa State University Veterinarian: Vol. 4
, Article 6.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol4/iss2/6