Columbia subject headings:
Catholic Church--Foreign relations--Russia.
Catholic Church--Relations--Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ.
Possevino, Antonio, 1533 or 1534-1611.
Russia--Foreign relations--Catholic Church.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--Relations--Catholic Church.
Harvard subject headings:
Catholic Church--Foreign relations--Russia.
Catholic Church--Relations--Russkai͡a pravoslavnai͡a t͡serkovʹ.
Possevino, Antonio, 1533 or 1534-1611.
Possevino, Antonio, 1534-1611.
Russia--Foreign Relations--Catholic Church.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--Foreign relations--Catholic Church.
Russkai︠a︡ pravoslavnai︠a︡ t︠s︡erkovʹ--Relations--Catholic Church.
Princeton subject headings:
Catholic Church--Foreign relations--Soviet Union.
Catholic Church--Relations--Orthodox Eastern Church, Russian.
Possevino, Antonio, 1534-1611.
Soviet Union--Foreign relations--Catholic Church.