Title: Uchastie bolgarskikh internat︠s︡ionalistov v Velikoĭ Okti︠a︡brʹskoĭ sot︠s︡ialisticheskoĭ revoli︠u︡t︠s︡ii i zashchite ee zavoevaniĭ
Subjects: Sources, History, Bulgarian Participation
Places: Soviet Union
Time periods: Revolution, 1917-1921