Columbia subject headings:
Europe--Social policy--Congresses.
Liberalism--Europe--History--Congresses.
Liberalism--Germany--History--Congresses.
Naumann, Friedrich, 1860-1919--Congresses.
Harvard subject headings:
Europe--Social policy--Congresses.
Liberalism--Europe--History--Congresses.
Liberalism--Germany--History--Congresses.
Naumann, Friedrich, 1860-1919--Congresses.
Princeton subject headings:
Europe--Social policy--Congresses.
Liberalism--Europe--History--Congresses.
Liberalism--Germany--History--Congresses.
Naumann, Friedrich, 1860-1919--Congresses.