Columbia subject headings:
Harvard subject headings:
Fire departments--Germany--History--20th century--Congresses.
Fire prevention--History--20th century--Congresses.
Germany--History--1933-1945--Congresses.
National socialism--Congresses.
Princeton subject headings:
Bombing, Aerial--Germany--History--Congresses.
Fire departments--Germany--History--Congresses.
World War, 1939-1945--Germany--Aerial operations--Congresses.