Columbia subject headings:
Harvard subject headings:
Environmental policy--Economic aspects--Europe, Central--History--Congresses.
Environmental policy--Economic aspects--Europe, Eastern--History--Congresses.
Industrialization--Europe, Central--History--Congresses.
Industrialization--Europe, Eastern--History--Congresses.
Nature conservation--Europe, Central--History--Congresses.
Nature conservation--Europe, Eastern--History--Congresses.
Socialism--Europe, Central--History--Congresses.
Socialism--Europe, Eastern--History--Congresses.
Princeton subject headings:
Environmental policy--Economic aspects--Europe, Central--History--Congresses.
Environmental policy--Economic aspects--Europe, Eastern--History--Congresses.
Industrialization--Europe, Central--History--Congresses.
Industrialization--Europe, Eastern--History--Congresses.
Nature conservation--Europe, Central--History--Congresses.
Nature conservation--Europe, Eastern--History--Congresses.
Socialism--Europe, Central--Congresses.
Socialism--Europe, Eastern--Congresses.