1. Jones DB (1931) Factors for converting percentages of nitrogen in foods and feeds into percentages of proteins. US Dept. Agric. Circular No. 183, August. USDA, Washington, DC
2. US Department of Agriculture, Agricultural Research Service (2016). USDA National Nutrient Database for Standard References, Release 28. Nutrient Data Laboratory Home Page. http://ndb.nal.usda.gov
3. AOAC International (2016) Official methods of analysis, 20th edn. (On-line). AOAC International, Rockville, MD
4. Yada RY, Jackman RL, Smith JL, Marangoni AG (1996) Analysis: quantitation and physical characterization, (Chapter 7). In: Nakai S, Modler HW (eds) Food proteins. Properties and characterization. VCH, New York, pp 333–403
5. Kolakowski E (2001) Protein determination and analysis in food system, (Chapter 4). In: Sikorski ZE (ed) Chemical and functional properties of food protein. Technomic Publishing, Lancaster, PA pp 57–112