Perhaps you should try some spelling variations:
regional conference » regional convergence, national conference, regional differences
regional reference » regional differences, regional resilience, regional convergence
origin references » brain references
algal origin » legal origin, glial origin, animal origin

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