Title: Po voprosu ob umstvennom utomlenīi trudi︠a︡shchikhsi︠a︡ li︠u︡deĭ voobshche, uchashchikhsi︠a︡ zhe di︠e︡teĭ, v chastnosti i o sposobakh ego izsli︠e︡dovanīi︠a︡
Subjects: Mental fatigue, Child mental health