Perhaps you should try some spelling variations:
change expert » changing expert, channel experts, change effect
change extent » change event, change latent, change extended
rica climate » africa climate, iea climate, america climate
group papers » group part
extent group » event group, patent group, extended group
ira climate » era climate, iea climate, area climate

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( oecd/rica climate change expert group papers ) OR ((( oecd/rica climate change extent group papers ) OR ( oecd/ira climate change extent group papers )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( oecd/rica climate change expert group papers ) or ((( oecd/rica climate change extent group papers ) OR ( oecd/ira climate change extent group papers ))))".
• Adding a wildcard symbol may retrieve word variants: (( oecd/rica climate change expert group papers ) or ((( oecd/rica climate change extent group papers ) OR ( oecd/ira climate change extent group papers ))))*.