[Hygienic evaluation of the duration of lessons of varying intensity].
D000065:Accommodation, Ocular; D001288:Attention / Q000502:physiology; D002490:Central Nervous System / Q000502:physiology; D005221:Fatigue / Q000503:physiopathology; D006801:Humans; D012572:School Health Services; D013997:Time Factors
Gigienicheskaia otsenka prodolzhitel'nosti zaniatiĭ pri raznoĭ ikh napriazhennosti.