1. Official method 982.23, Vitamin D in mixed feeds, premixes, and pet food -liquid 496 chromatographic method;Official Methods of Analysis,1983
2. Official method 2002.05, Cholecalciferol (vitamin D3) in selected foods. Liquid 499 chromatography;Aoac;Official Methods of Analysis,2012
3. Official method 2011.12, Vitamins D2 and D3 in infant formula and adult nutritionals: Ultra 502 pressure liquid chromatography with mass spectrometry detection (UPLC-MS/MS);Aoac;Official 503 Methods of Analysis,2012
4. Comparison of analysis of vitamin D3 in foods using ultraviolet and mass 508 spectrometric detection;W C Byrdwell;Journal of agricultural and food chemistry,2009
5. Survey of current vitamin D food fortification practices in the United 510 States and Canada;M S Calvo;The Journal of steroid biochemistry and molecular biology,2013