Columbia subject headings:
Science--History--20th century--Congresses.
Science--Social aspects--Congresses.
Technology--History--20th century--Congresses.
Technology--Social aspects--Congresses.
Harvard subject headings:
Science--History--20th century
Science--Social aspects
Princeton subject headings:
Science--History--20th century--Congresses.
Science--Social aspects--Congresses.
Technology--History--20th century--Congresses.
Technology--Social aspects--Congresses.