OSINT: The Ultimate Handbook for Cyber Sleuths

Operator Handbook: Red Team + OSINT + Blue Team Reference

The Grand Manifesto of OSINT: A Detective's Handbook: 1 (The Grand Codex of Intelligence)

OSINT 101 Handbook: Advanced Reconnaissance, Threat Assessment, And Counterintelligence

Financial Crime Investigator's Handbook: Using OSINT in financial crime hunting