Columbia subject headings:
Harvard subject headings:
Railroads--Canada--Timetables--Periodicals.
Railroads--Mexico--Timetables--Periodicals.
Railroads--North America--Passenger traffic--Periodicals.
Railroads--United States--Timetables--Periodicals.
Princeton subject headings:
Railroads--Canada--Timetables--Periodicals.
Railroads--Mexico--Timetables--Periodicals.
Railroads--North America--Passenger traffic--Periodicals.
Railroads--United States--Timetables--Periodicals.