Perhaps you should try some spelling variations:
"synchronised swimming" » "synchronized swimming"
"synchronising swimming" » "synchronizing swimming", "synchronisations swimming"
"synchronize swimming" » "synchronized swimming", "synchronizing swimming"
"synchronism stemming" » "synchronized stemming", "synchronism streaming", "synchronism steering", "synchronism flemming"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("synchronised swimming") or ("synchronising swimming"))) or ((("synchronize swimming") or ("synchronism stemming"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("synchronised swimming") OR ("synchronising swimming"))) OR ((("synchronize swimming") OR ("synchronism stemming")))).
• Removing quotes may allow a broader search: (((( synchronised swimming ) or ( synchronising swimming ))) or ((( synchronize swimming ) or ( synchronism stemming )))).
• Adding a wildcard symbol may retrieve word variants: (((("synchronised swimming") or ("synchronising swimming"))) or ((("synchronize swimming") or ("synchronism stemming"))))*.