Declassified Government Documents:
https://www.cia.gov/readingroom/collection/cia-analysis-soviet-navy
Personal Testimonies:
https://www.loc.gov/collections/veterans-history-project-collection/serving-our-voices/cold-war/cold-war-dispatches-service-stories-from-1947-to-1991/
Articles:
https://libraryguides.unh.edu/coldwarberwick/PrimarySources