FBI Freedom of Information Act Electronic Reading Room - Espionage  
   Declassified Federal Bureau of Investigation files, in .PDF format, on famous spy cases, including: Anthony Blunt; Burgess, MacLean and Philby; Owen Lattimore; Nathan Silvermaster; Julius and Ethel Rosenberg.
   http://foia.fbi.gov/spies.htm

National Counterintelligence Information Center (NACIC)  
   Provides national-level counterintelligence products and services for the US Government and the U.S. private sector.
   http://www.nacic.gov/

Of Moles and Molehunters  
   Former CIA officer Cleveland Cram surveys the literature on Counterintelligence Chief James Jesus Angleton's search for Soviet agents during the 1960s.
   http://www.cia.gov/csi/studies/95unclass/Cram.html

Kubark Counterintelligence: Interrogation  
   Handbook for Project KUBARK prepared in July 1963 by CIA's Counterintelligence Staff, designed for use in screening sources. Covers coercive and non-coercive methods; tips for resistant subjects; sensory deprivation and hypnosis. Includes interrogator's c
   http://www.parascope.com/articles/0397/kubark06.htm