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Drozd-Sokołowska JE, Dulny G, Waszczuk-Gajda A, Wiktor-Jędrzejczak W.Drozd-Sokołowska JE, et al. Among authors: dulny g.Przegl Epidemiol. 2014;68(4):621-6.Przegl Epidemiol. 2014.PMID: 25848780Free article.English, Polish.