The books contained in this list are ones that are written by individuals who are either (loosely or intricately) affiliated with the IC (unbeknownst to the public) or otherwise have sourced various material from the IC which has either leaked or otherwise been obtained.
Intelligence Agencies are rumored to engage with the public via podcasts and other pub-sub Internet engagements through a program called 'Internet Interactive Activities'. They may seek to provide truth, half-truths, and lies in order to get people thinking along certain lines.

Some of the common 'generalist interest' podcasts of which have hosted some of the below guests that have written on eccentric topics includes The Danny Jones Podcast, The Lex Fridman Podcast, The Chris Williamson Podcast, and The Joe Rogan Podcast, as well as some more niche podcasts with coverage of individuals and subjects such as The Destiny Podcast and The MATI Podcast.

Some of the guests who have written books include: Whitney Webb, Whitley Schreiber, Annie Jacobsen, Jason Jorjani etc.

Some of the books listed are some of which guests have written and presented as 'fiction', some of which that guests have referenced to or alluded to on the podcast but have been written by other authors, and some of which are based on a unique term, concept, or turn-of-phrase which the guest had broached on the podcast for which literature exists elsewhere.

Use your critical thinking skills to separate probable fact from probable fiction. Occam's Razor gets more complex the more you dig...