1. AAFCO 2010 Official Publication. The Association of American Feed Control Officials Illinois http://www.aafco.org/Publications/PublicationListing
2. Brody , S. Proctor , R. C. Ashworth , U. S. 1934 Growth and Development with Special Reference to Domestic Animals. XXXIV. Basal Metabolism, Endogenous Nitrogen, Creatinine and Neutral Sulphur Excretions as Functions of Bodyweight. Agricultural Experiment Station Research Bulletin No. 220 Columbia University of Missouri
3. Dogs large and small: The allometry of energy requirements within a single species;Burger;Journal of Nutrition.,1991
4. Evaluation of energy requirements of adult kennel dogs;Finke;Journal of Nutrition.,1991
5. A simple, reliable tool for owners to assess the body condition of their dog or cat;German;Journal of Nutrition.,2006