1. McCluno M. R. 1953. Heritability of productive characters in Duroc swine. Thesis No. 1477, Iowa State Coll., Ames. From abstract in Iowa St. Coll. J. Sci. 1955. 29: 455–56.
2. Litter size and weight as permanent characteristics of sows;Lush;Tech. Bull. U.S. Dept. Agric.,1942
3. The Variance of Intraclass Correlation Involving Groups with One Observation
4. Genetic Aspects of the Production Registry Program
5. King J. W. B. 1967. Pig breeding research.Proc. 9th int. Congr. Anim. Prod., Edinb.,1966, pp. 7–16.