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

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: (("inter regional reference") OR ("inter national conference")).
• Removing quotes may allow a broader search: (( inter regional reference ) or ( inter national conference )).
• Adding a wildcard symbol may retrieve word variants: (("inter regional reference") or ("inter national conference"))*.