Aryaev, N. L., I. M. Shevchenko, T. Y. Moskalenko, J. M. El Mezevgi, and N. V. Shevchenko. “Estimation of Probiotic and Vitamine D Efficiency in Prophylactics of Infectious Diseases in Premature Infants”. Journal of Education, Health and Sport, vol. 7, no. 6, June 2017, pp. 571-82, https://apcz.umk.pl/JEHS/article/view/4599.