Here are my favorite OSINT books: OSINT Techniques: Resources for Uncovering Online Information by Michael Bazzell Deep Dive: Exploring the Real-world Value of Open Source Intelligence by Rae Baker, Maritime SME, Private Inv, CISSP Baker OSINT: The Authoritative Guide to Due Diligence by Cynthia Hetherington The OSINT Handbook by Dale Meredith Operator Handbook by Netmux