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
During the past several years numerous studies on population fluctuations · for various game animals and birds have been made. The causes of many of these fluctuations are still unknown. During the past four months we have been able to observe a rapid decrease as it occurred in the Iowa cottontail (Sylvilagus floridanus mearnsi) and to determine the cause of the same.
Waller, E. F.
"Tularemia in Iowa Cottontail Rabbits (Sylvilagus jloridanus mearnsi) and in a Dog,"
Iowa State University Veterinarian: Vol. 2
, Article 5.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol2/iss2/5