https://en.wikipedia.org/wiki/Grand_Central_Terminal#Related_structures
https://en.wikipedia.org/wiki/Park_Avenue_Viaduct
https://en.wikipedia.org/wiki/Grand_Central_Terminal#Innovations
https://upload.wikimedia.org/wikipedia/commons/9/99/Grand_Central_Terminal_-_Sectional_View_1939.jpg
https://en.wikipedia.org/wiki/Grand_Central_Terminal#Terminal_City
https://en.wikipedia.org/wiki/Grand_Central_Terminal#Services
https://upload.wikimedia.org/wikipedia/commons/3/3d/RailUS_GCT-upperTracksPlan.gif
https://upload.wikimedia.org/wikipedia/commons/6/61/RailUS_GCT-lowerTracksPlan.gif