Columbia subject headings:
Harvard subject headings:
Bus lines--Fares--Congresses.
Bus lines--Marketing--Congresses.
Local transit--Fares--Congresses.
Local transit--Marketing--Congresses.
Princeton subject headings:
Bus lines--Fares--Congresses.
Bus lines--Marketing--Congresses.
Local transit--Fares--Congresses.
Local transit--Marketing--Congresses.