Between 1992 and 1999, Spain's Ejército del Aire became one of the first NATO air forces to systematically declassify its UFO archive. 86 case files · ~1,900 pages spanning 1962-1995 were released under General Alfredo Chamorro Chapinal. The files are held at the Archivo Histórico del Ejército del Aire. Source: ejercitodelaire.defensa.gob.es.
Cards below deep-link into the official catalogs and institutional pages. Where direct PDFs were reachable they're mirrored locally; everything else opens on the live source.