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
Ventricular myopathy or avitaminosis-E of turkeys is quite uncommon. The affection is rarely encountered in the field, the usual incidence being less than one percent in a given flock. However, when the incidence increases to 60 percent, it stimulates the interest of those people concerned with the turkey industry.
Firkins, George S.
Iowa State University Veterinarian: Vol. 16
, Article 2.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol16/iss1/2