- American Mafia – Fiction and non-fiction books on organized crime
- FBI “The Vault” – FBI files, including those dealing with the “Gangster Era” and “organized Crime”
- Gray Literature Database – A searchable database of mostly unpublished publications from the Library of Criminal Justice at Rutgers University.
- National Criminal Justice Reference Service – Comprehensive searchable bibliographic criminal justice databases
- Public Safety Canada Organized Crime Research Includes research reports commissioned by Public Safety Canada
- RCMP Publications – Numerous other publications produced by the RCMP, including many addressing organized crime issues.
- Library of Congress – Largest collection of books in the world
- Amazon.com – The second largest collection of books in the world
- Google Books – The third largest collection of books in the world