Kokorkin, D.M. , Skorobogaty, V.V. , Gusakova, O.O. , Shevlyuk, P.P. and Kolyada, N.A. 2021. From secretory otitis to retraction cholesteatoma. Modern medical technology. 3 (Sep. 2021), 31–34. DOI:https://doi.org/10.34287/MMT.3(50).2021.6.