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1. Davis C.Y. Effect of all-trans Retinol and Retinoic Acid Nutritive on the Immune System of Chicks / C. Y. Davis, I. L. Sell // 1. Nutr. 2003. Vol. 113. Pp.1914-1919.
2. Khenning A. Mineral Substances, Vitamins, Biostimulants in Feeding of Agricultural Animals. Moscow: Kolos, 2010. 558 p.
3. Valdman A.R., Surai P.F., Ionov I.A., Sakhatsky N.I. Vitamins in Animal Feed (Metabolism and Requirement). – Kharkov: publishing house: Original, 1993. 423 p.
4. Vasilenko V.N., Makarova I.V. Hematologic Indices of Broiler-chickens after Using L-Carnitin in their Diet. / V.N. Vasilenko, I.V. Makarova // Poultry and poultry products. 2009.  №1. Pp. 45-46.
5. Maslyuk, A.N. The Effect of Different Doses of Ascorbic and Nicotinic Acids on Morphofunctional Parameters of the Males-broilers: Abstract dis. .. candidate of biol. Sciences. Ekaterinburg, 2007. 22 p.: ill.
6. Bevzyuk V.N. Unconventional Feed and Enzyme Preparations in the Feed of Meat Poultry: Abstract dis. ... Dr. agricultural Sciences. settl. Persianovsky, 2005. 47 p.
7. Mordakin V.N. Economic and Biological Characteristics of Broiler-chickens of "Smena-4" Cross Fed on Ascorbic, Citric and Fumaric Acids: Abstract dis. ... candidate of agricultural Sciences. Ryazan, 2006. 18 p.