ICAO regulation on UFBs, 1977

ICAO regulation on UFBs, 1977, - 04 03 ATD 3 Sub- 3 Box 4 Folder 9, Box: 4, Folder: 9. Atmospheric Technology Division (ATD) Records, - 04-03-ATD. National Center for Atmospheric Research (NCAR) Archives. https://aspace.archives.ucar.edu/repositories/2/archival_objects/4912 Accessed April 18, 2026.