1. Cage layer fatigue is a complicated problem;Abdul-Aziz;World Poult.,1998
2. Aviary systems and conventional cages for laying hens;Abrahamsson;Acta Agric. Scand.,1995
3. Comparison of bone characteristics of hens of three different ages in cages and floor pens;Arafa;Appl. Agric. Res.,1987
4. Quantitative trait loci for femoral and lumbar vertebral bone mineral density in C57BL/6J and C3H/HeJ inbred strains of mice;Beamer;J. Bone Miner. Res.,2001
5. Bone problems an increasing ailment in layers;Belyavin;World Poult.,1995