Columbia subject headings:
Organ (Musical instrument)--Baltic Sea Region--Congresses.
Organ music--Baltic Sea Region--Congresses.
Organists--Baltic Sea Region--Congresses.
Harvard subject headings:
Organ (Musical instrument)--Baltic Sea Region--Congresses.
Organ music--Baltic Sea Region--Congresses.
Organists--Baltic Sea Region--Congresses.
Princeton subject headings:
Organ (Musical instrument)--Baltic Sea Region--Congresses.
Organ music--Baltic Sea Region--Congresses.
Organists--Baltic Sea Region--Congresses.