Zaharieva , K., Nedeva , T. and Sherbanov , O. 2021. HARDENING OF CHILDREN UNDER 3 YEARS OF AGE – AN IMPORTANT COMPONENT OF DISPOSITION PROPHYLAXIS . EurasianUnionScientists. 2, 12(81) (Jan. 2021), 30-34. DOI:https://doi.org/10.31618/ESU.2413-9335.2020.2.81.1150.