Columbia subject headings:
Catholic Church--Baltic States--History--Congresses.
Estonia--Church history--Congresses.
Latvia--Church history--Congresses.
Livonia--Church history--Congresses.
Harvard subject headings:
Baltic States--Church history--Congresses.
Princeton subject headings:
Catholic Church--Baltic States--History--Congresses.
Estonia--Church history--Congresses.
Latvia--Church history--Congresses.
Livonia--Church history--Congresses.