Perhaps you should try some spelling variations:
"la regional conferences" » "la regional conference", "la regional consequences", "la regional differences", "a regional conferences", "ia regional conferences", "sea regional conferences"
"das original conference" » "das regional conference", "das optical conference", "das final conference", "his original conference"
"its original conference" » "its regional conference", "its optical conference", "its final conference", "its origin conference", "his original conference"
"das retinal conference" » "das regional conference", "das retrieval conference", "das national conference", "das retinale conference", "gas retinal conference", "does retinal conference"

Try widening your search to All Fields.

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: (("la regional conferences") OR ((((("das original conference") OR ("das retinal conference"))) OR ("its original conference")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"la regional conferences\") or (((((\"das original conference\") OR (\"das retinal conference\"))) or (\"its original conference\"))))".
• Removing quotes may allow a broader search: (( la regional conferences ) or ((((( das original conference ) OR ( das retinal conference ))) or ( its original conference )))).
• Adding a wildcard symbol may retrieve word variants: (("la regional conferences") or ((((("das original conference") OR ("das retinal conference"))) or ("its original conference"))))*.