Perhaps you should try some spelling variations:
22policy research » policy research, police research, polity research
workshop paper » workshop papers, workshop papm, workshop cape
workshop panel » workshops panels, workshop papers, workshop paris
workshop para » workshop paris, workshop papers, workshop program

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: %22policy research ((workshop paper) OR (((workshop panel) OR (workshop para))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22policy research ((workshop paper) or (((workshop panel) OR (workshop para))))%22".
• Adding a wildcard symbol may retrieve word variants: %22policy research ((workshop paper) or (((workshop panel) OR (workshop para))))%22*.