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
On the morning of Dec. 23, 1940, the author was summoned to see a four year old Holstein cow. The owner said she had become ill the previous day.
Kufrin, R. S.
Iowa State University Veterinarian: Vol. 3
, Article 19.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol3/iss3/19