1. Association of Official Agricultural Chemists, 1960. Official Methods of Analysis, 9th Ed., Washington, D.C.
2. Phosphorus and laying hen performance;Crowley;Poultry Sci.,1961
3. Multiple range and multiple F tests;Duncan;Biometrics,1955
4. The effects of feeding various levels and sources of phosphorus to laying hens;Harms;Florida Agr. Expt. Sta. Bui.,1961
5. Re-evaluation of the phosphorus requirement of the laying hen;Marr;Poultry Sci.,1961