Burby signed a pledge to co-operate with Czechoslovak intelligence, promising to 'fulfil all tasks assigned to me' and maintain 'absolute secrecy' about his role.

Source: https://www.dailymail.co.uk/news/article-12300621/The-Cold-Wars-brazen-betrayal-saw-traitor-send-postcards-Queen-handlers.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

He was on the Czechoslovak team at the 1984 Canada Cup.

Source: https://chicago.suntimes.com/2023/5/4/23711343/petr-klima-stanley-cup-winning-czech-forward-dies-at-58

Slovak and Czech history was deeply intertwined even before the two nations were joined together in the Czechoslovak Republic more than a century ago.

Source: https://spectator.sme.sk/c/23161788/whats-new-in-slovak-science-erc-grant-drought-ends.html

They were Czechoslovak Group, Colt CZ Group, Omnipol and STV GROUP, the official said.

Source: https://newsinfo.inquirer.net/1760386/czech-republic-looks-to-supply-vietnam-more-aircraft-radars-source