[Hygienic requirements for the class lessons of schoolchildren].
D002648:Child; D006801:Humans; D006920:Hygiene; D007374:Interior Design and Furnishings; D005222:Mental Fatigue / Q000517:prevention & control; D012573:School Nursing; D013663:Teaching / Q000379:methods*; D013997:Time Factors; D014586:USSR
Gigienicheskie trebovaniia k uchebnym zaniatiiam shkol'nikov.