Columbia subject headings:
Economic development--Environmental aspects--Directories.
Environmental policy--Congresses--Directories.
Environmental protection--Congresses--Directories.
Natural resources--Congresses--Directories.
United Nations Conference on Environment and Development (1992 : Rio de Janeiro, Brazil)--Congresses.
Harvard subject headings:
Earth Summit (1st : 1992 : Rio de Janeiro, Brazil)--Directories.
Environmental policy--Directories.
Environmental protection--Directories.
Princeton subject headings: