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 evening of February 21st, an eight year old Cheviot ewe was noticed by the owner to be having difficulties lambing. He observed that a small portion of the fetal placenta was hanging from the vulva of the ewe. His attempts to deliver the lambs were not successful.
"Ovine Dystocia Caused by an Abdominal Distention of the Fetus,"
Iowa State University Veterinarian: Vol. 22
, Article 13.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol22/iss3/13