In February 1992 the transcripts were declassified and published. Documents about the project were declassified in 2001. Results of this wartime research were declassified and published in 1953. The Czechs and Hungarians had declassified related documents in the 1990s. The CIA declassified documents related to Area 51 and recognized its existence in 2013. In November 2006, photographs showing Soviet atrocities were declassified by the Finnish authorities. In June 2011, the entirety of the "Pentagon Papers" was declassified and publicly released. The UDTs and flamethrowing tanks are declassified top secret examples. It was published in conjunction with an archive of nearly 100 declassified diplomatic cables. Numerous photographs of various thermonuclear bomb exteriors have been declassified. These tapes were not declassified and revealed for some time. In April 2020 the footage was declassified and officially released by the Department of Defense. According to the government, the reports had been inadvertently declassified. The discovery was declassified and published in 1973. The results of this study were not published until 1946, when they were declassified.