Perhaps you should try some spelling variations:
preschool performance » school performance, prediction performance, present performance
improving preschool » improving school, improved preschools, improving schools
performance metrics » performance measures
performance series » performance studies, performance size
improving thermal » improving external, improving animal, improving erm

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

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