Columbia subject headings:
Applied human geography--Congresses.
Drug addiction--Environmental aspects--Congresses.
Drug addiction--Etiology--Congresses.
Drug addiction--Mathematical models--Congresses.
Drug addiction--Social aspects--Congresses.
Medical geography--Congresses.
Harvard subject headings:
Applied human geography--Congresses.
Drug addiction--Environmental aspects--Congresses.
Drug addiction--Etiology--Congresses.
Drug addiction--Mathematical models--Congresses.
Drug addiction--Social aspects--Congresses.
Epidemiology
Geography
Human geography
Medical geography--Congresses
Social sciences
Sociology
Princeton subject headings: