1. Bezpa, J., O. F. Johndrew, G. H. Thacker, R. M. Grover, F. V. Muir and C. A. Dupras, 1972. Field studies on egg shell damage and bloodspot detection. Extension Bulletin 403, Northeast Regional Publication, Cooperative Extension Service, Rutgers University, New Brunswick, New Jersey 08903.
2. Federal Register, 1971. Egg and Egg Products Inspection, Vol. 36(104).
3. Factors influencing egg shell quality—a review.;Petersen;World’s Poultry Sci. J.,1965
4. Statistical Methods Applied to Experiments in Agriculture and Biology.;Snedecor,1957
5. Factors influencing egg shell quality—a review.;Wolford;World’s Poultry Sci. J.,1970