Columbia subject headings:
Harvard subject headings:
Air quality management--Economic aspects--United States--Congresses.
Air quality management--Government policy--United States--Congresses.
Air--Pollution--Economic aspects--United States--Congresses.
Air--Pollution--Government policy--United States--Congresses.
Princeton subject headings:
Air quality management--Economic aspects--United States--Congresses.
Air quality management--Government policy--United States--Congresses.
Air--Pollution--Economic aspects--United States--Congresses.
Air--Pollution--Government policy--United States--Congresses.