Columbia subject headings:
Conservation of natural resources--United States.
Industrial ecology--United States.
Materials management--United States.
Recycled products--United States.
Harvard subject headings:
Conservation of natural resources--United States.
Industrial ecology--United States.
Materials management--United States.
Recycled products--United States.
Princeton subject headings:
Conservation of natural resources--United States.
Industrial ecology--United States.
Materials management--United States.
Recycled products--United States.