http://www.irsd.be/website/images/livres/rmb/19/ed_19_art_16.pdf
https://www.aspistrategist.org.au/from-the-bookshelf-spies-the-epic-intelligence-war-between-east-and-west/
https://www.bennettinstitute.cam.ac.uk/wp-content/uploads/2023/01/A_World_Divided.pdf