*United States. National Counterintelligence Center. [http://www.nacic.gov/history/CIReaderPlain/Vol3Chap1.pdf. ''A Counterintelligence Reader'', Vol 3 Chap 1]. NACIC. no date. pg. 31.
*United States. National Counterintelligence Center. [http://www.nacic.gov/history/CIReaderPlain/Vol3Chap1.pdf. ''A Counterintelligence Reader'', Vol 3 Chap 1]. NACIC. no date. pg. 31.
*File card of Patterson contacts in regard Silvermaster, box 203, Robert P. Patterson papers, Library of Congress
*File card of Patterson contacts in regard Silvermaster, box 203, Robert P. Patterson papers, Library of Congress