Columbia subject headings:
Central places--Mathematical models--Congresses.
City planning--Methodology--Congresses.
Regional planning--Methodology--Congresses.
Space in economics--Mathematical models--Congresses.
Harvard subject headings:
Central places--Mathematical models--Congresses.
City planning--Methodology--Congresses.
Regional planning--Methodology--Congresses.
Space in economics--Mathematical models--Congresses.
Princeton subject headings: