Utopian literature of the 20th century

Hello everyone !

I am working on the affinities between Mustapha Mond, the World Controller of Brave New World, and Plato's philosopher king to eventually conclude that the BNW city state is a Eutopian/utopian one. I currently need any book titles speaking about how the concept of utopianism changed during the 20th century; denouncing any form of authoritarian government and how it changed once again during the 21st century; which is why Brave New World does not seem as the hellish nightmare it once was when it was first published.

I am quite lost of how to contextualise for the idea, any help or insight would be appreciated