3Riddell C. Pathology of developmental and metabolic disorders of the skeleton of domestic chickens and turkeys abnormalities due to nutritional or toxic factors [J]. Veterinary Bulletin, 1975, C 10 ): 705-7i8.
4Riddell C. Skeletal deformities in poultry [J]. Advances in Veterinary Science and Comparative Medicine, 1981,25: 277-3101.