Columbia subject headings:
Harvard subject headings:
Drug abuse--European Economic Community countries--Epidemiology--Methodology.
Public health surveillance--European Economic Community countries.
Princeton subject headings:
Drug abuse surveys--European Economic Community countries--Congresses.
Drug abuse--European Economic Community countries--Forecasting--Congresses.
Drug utilization--European Economic Community countries--Evaluation--Congresses.
Epidemiology--European Economic Community countries--Congresses.