Not read this.

I quite like Jacques Vallee

This https://www.goodreads.com/book/show/406344.Passport_to_Magonia

And

https://www.goodreads.com/en/book/show/406348

Sounds like there may be some overlap. Although Vallee is definitely a lot more ambiguous. He's an interesting character, was around for the invention of arpanet. The French scientist in Close Encounters was based on him.