KhomichV.Т., Dyshliuk, N.V., Mazurkevych, T.A., GuralskаS.V. and UsenkoS.І. 2021. Content and location of lymphocyte subpopulations with markers CD4+, CD8+ and CD20+ in the esophageal tonsil of chickens and the Meckel diverticulum of ducks . Regulatory Mechanisms in Biosystems. 12, 3 (Aug. 2021), 396-402. DOI:https://doi.org/10.15421/022154.