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
A 3-year-old neutered male Persian cat was presented with a history of gagging and vomiting solid food for about two months. The cat would keep down liquids and soft food, but had lost weight.
Wilson, Christ and Mitten, Russell W.
"What's Your Radiographic Diagnosis?,"
Iowa State University Veterinarian: Vol. 43
, Article 8.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol43/iss1/8