Van Den Brand H, Parmentier HK, Kemp B (2004). "Effects of housing system (outdoor v. cages) and age of laying hens on egg characteristics". Br. Poult. Sci. 45 (6): 745–52. doi:10.1080/00071660400014283. PMID15697013. S2CID26468071.
Van Den Brand H, Parmentier HK, Kemp B (2004). "Effects of housing system (outdoor v. cages) and age of laying hens on egg characteristics". Br. Poult. Sci. 45 (6): 745–52. doi:10.1080/00071660400014283. PMID15697013. S2CID26468071.
Van Den Brand H, Parmentier HK, Kemp B (2004). "Effects of housing system (outdoor v. cages) and age of laying hens on egg characteristics". Br. Poult. Sci. 45 (6): 745–52. doi:10.1080/00071660400014283. PMID15697013. S2CID26468071.