Peculiarities of mental efficiency and progress of higher grades students began studying at the age of six and seven. Environment & Health, [S. l.], v. 85, n. 1, p. 73–76, 2018. DOI: 10.32402/dovkil2018.01.073. Disponível em: https://dovkil-zdorov.kiev.ua/journal/article/view/442. Acesso em: 26 apr. 2026.