1. Quit breaking those egg shells-it's costing you money;Bezpa;Poultry Tribune,1972
2. Multiple range test and multiple F tests;Duncan;Biometrics,1955
3. Management factors affecting shell quality;Elson;Agriculture,1968
4. Forsythe, R. H., 1966. Modern marketing demands sound shells. Proc. Egg Shell Quality Conference. Univ. of Nebraska, Lincoln, Nebraska.
5. Some interesting egg monstrosities;Hargitt;Zoo. Bull.,1899