Perhaps you should try some spelling variations:
regional conference » regional convergence, regional differences
national conference » international conference
regional reference » regional differences, regional resilience, regional convergence
global conference » annual conference
elter regional » better regional, center regional, inter regional
inter » unter

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: (( elter regional reference ) OR ( inter ((((regional conference) OR (global conference))) OR (national conference)) ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( elter regional reference ) or ( inter ((((regional conference) OR (global conference))) or (national conference)) ))*".