Perhaps you should try some spelling variations:
"elter national conference" » "elter international conference", "alter national conference", "center national conference", "better national conference"
"inter regional science" » "inter national science", "inter regional scale", "unter regional science"

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