Title: Nauchno-tekhnicheskata revoli︠u︡t︠s︡ii︠a︡ v deĭnostta na pionerskata organizat︠s︡ii︠a︡
Subjects: Educational innovations, Communist education, Dimitrovska pionerska organizat︠s︡ii︠a︡ "Septemvriĭche."
Places: Bulgaria