Columbia subject headings:
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--History--20th century.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ. Pomestnyĭ sobor.
Soviet Union--History--Revolution, 1917-1921.
Harvard subject headings:
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--History--20th century.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ. Pomestnyĭ sobor
Soviet Union--History--Revolution, 1917-1921.
Princeton subject headings:
Church and state--Soviet Union--History.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--History--20th century.
Soviet Union--Church history.
Soviet Union--History--Revolution, 1917-1921.