00542naa#a2200181#i#450# EN\INFRA-M\bibl\2152 20260226140248.4 2075-4094 20141105b2014####ek#y0engy0150####ca RUS RU A survey of pre-school children who are often ill and the ways of their improvement Journal article Moscow INFRA-M Academic Publishing LLC. 2014 4 с. Journal article local Vorontsova Zoya Kosobutskaya S. zh-szf.ru