Columbia subject headings:
Electric railroads--Location--Cost effectiveness.
Local transit--Mathematical models.
Street-railroads--Location--Cost effectiveness.
Harvard subject headings:
Electric railroads--Location--Cost effectiveness.
Local transit--Mathematical models.
Street-railroads--Location--Cost effectiveness.
Princeton subject headings:
Electric railroads--Location--Cost effectiveness.
Local transit--Mathematical models.
Street-railroads--Location--Cost effectiveness.