I don’t see it mentioned yet, so I’ll add van Vogt, A. E., The World of Null-A. 1948 https://en.wikipedia.org/wiki/The_World_of_Null-A https://en.wikipedia.or

I don’t see it mentioned yet, so I’ll add van Vogt, A. E., The World of Null-A. 1948 https://en.wikipedia.org/wiki/The_World_of_Null-A https://en.wikipedia.org/wiki/The_World_of_Null-A https://www.google.com/search?q=world+of+null-a https://www.google.com/search?q=world+of+null-a