Shanghai Metro - Wikipedia
R4 (New York City Subway car) - Wikipedia
Metropolitan Transportation Authority - Wikipedia
6 (New York City Subway service) - Wikipedia
L (New York City Subway service) - Wikipedia
New York metropolitan area - Wikipedia
IRT Broadway – Seventh Avenue Line | Metro Wiki | Fandom
History of the New York City Subway - Wikipedia
Canal Street station (New York City Subway) - Wikipedia
New York City Subway - Wikipedia
Metro-North Railroad - Wikipedia
New York City Subway - Wikipedia
J/Z (New York City Subway service) - Wikipedia
New York City Subway nomenclature - Wikipedia
4 (New York City Subway service) - Wikipedia
New York City Subway - Wikipedia
List of metro systems - Wikipedia
New York City Subway - Wikipedia
Interborough Rapid Transit Company - Wikipedia
New York City Subway - Wikimedia Commons
Technology of the New York City Subway - Wikipedia
A (New York City Subway service) - Wikipedia
F (New York City Subway service) - Wikipedia
New York City Subway - Wikidata
