DC TV universe explained – How The Flash, Supergirl, Arrow and Earths 1-3 fit together

How Supergirl, The Flash and Arrow fit together.

Crisis on Earth-X, Arrowverse Wiki

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CW Superhero Shows 'The Flash,' 'Arrow' and 'Supergirl' to Get Audio Series - TheWrap

DC's April 2023 solicitations

DC TV universe explained – How The Flash, Supergirl, Arrow and Earths 1-3 fit together

Will the Arrowverse create their own version of the Justice League? Will the CW get a budget increase so they can have characters such as the Green Lantern or the Anti-Monitor?

Superman and Lois” Ordered to Series at The CW — “Supergirl” Spinoff – TVLine

Roy Harper - News - IMDb

The CW DC SuperHero Trilogy: Supergirl, Flash, and Arrow - Binge Watcher's Council

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DC Crisis on Infinite Earths Explained, CW Arrow,Flash,Supergirl Crossover