Columbia subject headings:
Harvard subject headings:
Air--Pollution--European Union countries.
Atmospheric ozone--Environmental aspects--European Union countries.
Atmospheric ozone--European Union countries.
Tropospheric circulation--Environmental aspects--European Union countries.
Tropospheric circulation--European Union countries.
Princeton subject headings:
Atmospheric ozone--European Union countries.
Atmospheric ozone--Physiological effect.
Crops--Effect of atmospheric ozone on--European Union countries.
Ozone layer--European Union countries.
Trospheric circulation--Environmental aspects--European Union countries.
Trospheric circulation--European Union countries.