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 October 20, 1941, an eleven-year-old Shorthorn cow was brought into the Stange Memorial Clinic. The owner reported that the cow was bred Jan. 10, 1941, and that it was time for a normal pregnancy to terminate. He also stated that the cow was in labor for several hours.
Tobola, R. J.
"Unusual Maternal Dystocia,"
Iowa State University Veterinarian: Vol. 4
, Article 14.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol4/iss2/14