1. Aviary systems and conventional cages for laying hens. Effects on production, egg quality, health and birds’ location in three hybrids. Acta Agric;Abrahamsson;Scand. Sect. A, Anim. Sci.,1995
2. Performance of four hybrids of laying hens in modified and conventional cages. Acta Agric;Abrahamsson;Scand. Sect. A, Anim. Sci.,1995
3. Shell and interior quality and chemical composition of eggs from hens of different strains and ages fed different dietary lysine levels;Al Bustany,;Acta Agric. Scand.,1987
4. Official Methods of Analysis,1984
5. Natural products for egg yolk pigmentation. Pages 47–68 in: Recent Development in Poultry Nutrition. 1. Poultry Nutrition;Belyavin,1989