Columbia subject headings:
Environmental protection--Developing countries--Statistics--Periodicals.
Environmental protection--Statistics--Periodicals.
Organisation for Economic Co-operation and Development--Statistics--Periodicals.
Pollution--Developing countries--Statistics--Periodicals.
Pollution--Statistics--Periodicals.
Harvard subject headings:
Environmental protection--Developing countries--Statistics--Periodicals.
Environmental protection--Statistics--Periodicals.
Organisation for Economic Co-operation and Development--Statistics--Periodicals.
Periodicals
Pollution--Developing countries--Statistics--Periodicals.
Pollution--Statistics--Periodicals.
Statistics
Princeton subject headings:
Environmental protection--Statistics--Periodicals.
Pollution--Statistics--Periodicals.