1. Replacing versus not replacing laying hens removed from cages;Adams;Poultry Sci.,1974
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3. Cage shape and density considerations for maximum profits;Bell,1977
4. Bell, D. D., 1985. Economic appraisal of cage density. Poultry Trib. 14–18.
5. Bell, D. D., and M. H. Swanson, 1975. Crowding chickens in cages reduces your profits. California Coop. Ext. Ser. L-2273.