Columbia subject headings:
Archivio vaticano.
Germany--Church history--843-1517.
Pacifists--Germany--Biography.
Quidde, Ludwig, 1858-1941.
Harvard subject headings:
Church records and registers--Germany--History--Congresses.
Germany--Church history--Congresses.
Germany--History--Sources--Congresses.
Pacifists--Germany--Biography--Congresses.
Quidde, Ludwig, 1858-1941--Congresses.
Princeton subject headings:
Archivio vaticano.
Germany--Church history--843-1517.
Pacifists--Germany--Biography.
Quidde, Ludwig, 1858-1941.