RT null T1 2020 World Ozone Day in Nepal A1 Nepal, K1 ozone layer PB Nepal Bureau of Standard and Metrology YR 2020 FD 2020 LK https://wedocs.unep.org/handle/20.500.11822/34202 UL https://wedocs.unep.org/handle/20.500.11822/34202 NO In observation of World Ozone Day, 16 September 2020 DS UN Environment Document Repository RD Sep 24, 2026