Perhaps you should try some spelling variations:
performance contract » performance contracts
performance series » performance studies, performance size
past performance » plant performance, port performance, transit performance
und performance » fund performance, funds performance, good performance
improving past » improving fast, improving post, improving plant
improving und » improving food, improving burn, improving feed

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

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