https://loopchicago.com/in-the-loop/then-and-now-a-brief-history-of-the-chicago-l/
https://www.etsy.com/listing/277771328/chicago-photography-the-el-train-chicago 8
https://www.cgccusa.org/en/chinas-crrc-wins-1-3-bln-deal-to-supply-chicago-rail-cars 8
https://www.etsy.com/ie/listing/231304693/chicago-photography-loop-cta-train-black 6
https://en.wikipedia.org/wiki/Purple_Line_(CTA)#/media/File:Argyle_and_Bryn_Mawr.jpg 6
https://www.capehorn-illustration.com/products/chicago-elevated-lines-the-rolling-stock-11-x-14-18-x-24
https://en.wikipedia.org/wiki/Chicago_%22L%22#Lines
https://www.transitchicago.com/howto/riding-the-train/
https://www.chicago-l.org/history/CTA4.html
https://www.youtube.com/watch?v=ecuJEoH4PMk
#/media/File:Argyle_and_Bryn_Mawr.jpg){kind=link}