1. Recommended Nutrient Allowances for Poultry;NRC,1944
2. Nutrient Requirements of Poultry;NRC,1984
3. Nutrient Requirements of Poultry;NRC,1994
4. United States Government. 2011. 5 USC § 552: Public information
5. agency rules, opinions, orders, records, and proceedings. Accessed Jun. 11, 2014. http://www.gpo.gov/fdsys/pkg/USCODE-2010-title5/pdf/USCODE-2010-title5-partI-chap5-subchapII-sec552.pdf