Perhaps you should try some spelling variations:
performance metrics » performance measures
local performance » social performance, global performance, total performance
birth performance » high performance, growth performance, health performance
improving local » improving global, improving fiscal
improving birth » improving air, improving health, improving growth

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: (( improving local performance metrics. ) OR ( improving birth performance evidence. ))~.
• Adding a wildcard symbol may retrieve word variants: (( improving local performance metrics. ) or ( improving birth performance evidence. ))*.