Perhaps you should try some spelling variations:
performance metrics » performance measures
performance series » performance studies, performance size
mental performance » general performance, senegal performance, annual performance
urban performance » bank performance, loan performance, human performance
improving mental » improving maternal, improving fiscal, improving gender

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( improving urban performance series. ) or ( improving mental performance metrics. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( improving urban performance series. ) OR ( improving mental performance metrics. )).
• Adding a wildcard symbol may retrieve word variants: (( improving urban performance series. ) or ( improving mental performance metrics. ))*.