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

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( elter regional reference ) OR ( inter ((regional conference) OR (national conference)) ))".
• Adding a wildcard symbol may retrieve word variants: (( elter regional reference ) OR ( inter ((regional conference) OR (national conference)) ))*.