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
Hog cholera tissue vaccine is a product made under stringent regulation of the United States Bureau of Animal Industry, and distributed under license specifying "for field trial use by qualified veterinarians only."
Boynton, William H.; Woods, Gladys M.; Wood, F. F.; Casselberry, N. H.; and Dykstra, L. A.
"B.T. V. in Hog Cholera,"
Iowa State University Veterinarian: Vol. 4
, Article 3.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol4/iss3/3