World's first Underground | London Transport Museum
First underground train, Edgware Road to Kings Cross, London Stock Photo - Alamy
The world's first subway opened in London | History.info
Where was the first metro rail in the world? - Quora
A short history of world metro systems – in pictures | Cities | The Guardian
World's oldest metro systems - Railway Technology
A Pictorial History of the London Tube and Its Graphic Legacy – The Marginalian
Tube - Transport for London
How the world's first metro system was built - Christian Wolmar - YouTube
New London Subway Trains to Be Fully Automatic -- Occupational Health & Safety
File:Tube150 - Metropolitan Railway No. 1 Steam Train at Great Portland Street Tube Station.jpg - Wikimedia Commons
The History Of The Tube Map | Londonist
A very short history of the Underground | London Transport Museum
Another world first for London Underground: energy from braking trains | The Knowledge Exchange Blog
Subway | History, Transportation, Cities, & Facts | Britannica
Subway | History, Transportation, Cities, & Facts | Britannica
London Underground: Night Tube to return for first time since March 2020 | UK News | Sky News
London Underground First Person Journey - Knightsbridge to Aldgate via Holborn and Liverpool Street - YouTube
First Day of the London Tube | History Today
First underground trains 1863 hi-res stock photography and images - Alamy
The World's Oldest Metro Systems - WorldAtlas
A history of the London Underground - CBBC Newsround
