List of metro systems - Wikipedia
Interborough Rapid Transit Company - Wikipedia
6 (New York City Subway service) - Wikipedia
New York City Subway - Wikipedia
Metropolitan Transportation Authority - Wikipedia
R110A (New York City Subway car) | Metro Wiki | Fandom
New York City Subway - Wikipedia
Washington Metro - Wikipedia
Technology of the New York City Subway - Wikipedia
New York City Subway - Wikimedia Commons
L (New York City Subway service) - Wikipedia
Canal Street station (New York City Subway) - Wikipedia
Mexico City Metro - Wikipedia
New York City Subway - Wikidata
Montreal Metro - Wikipedia
New York City Subway - Wikiwand
New York City Subway - Wikipedia
History of the New York City Subway - Wikipedia
New York City Subway nomenclature - Wikipedia
New York City Subway - Wikipedia
Paris Métro - Wikipedia
Shanghai Metro - Wikipedia
