Oliyar, A. V., P. M. Skliarov, D. M. Masiuk, D. D. Bilyi, V. V. Logvinova, and M. A. Lieshchova. “Effect of β-Mannanase Enzyme Supplementation on the Morphofunctional State of Broiler chickens’ Immunocompetent Organs ”. Regulatory Mechanisms in Biosystems, Vol. 11, no. 4, Nov. 2020, pp. 579-87, doi:10.15421/022090.