L. Lubarska, N. Yemchenko, and M. Hulich, “The actual content of zinc and copper trace elements in the food intake of the children at preschool educational institutions in Kyiv”, Environment & Health, vol. 75, no. 4, pp. 47–50, Oct. 2015, Accessed: Aug. 24, 2026. [Online]. Available: https://dovkil-zdorov.kiev.ua/journal/article/view/585