Perhaps you should try some spelling variations:
regional convergence » global convergence
regional conference » regional differences, global conference
national conference » international 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 convergence ) OR ( inter ((regional conference) OR (national conference)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( elter regional convergence ) or ( inter ((regional conference) OR (national conference)) ))".
• Adding a wildcard symbol may retrieve word variants: (( elter regional convergence ) or ( inter ((regional conference) OR (national conference)) ))*.