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

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