Perhaps you should try some spelling variations:
"synchronised swimming" » "synchronism swimming", "synchronising swimming", "synchronised stemming"
"synchronizing swimming" » "synchronizing stemming"
"synchronize swimming" » "synchronize stemming", "synchronism swimming"
"synchronized swimming" » "synchronized stemming", "synchronismd swimming"

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 ("synchronizing swimming"))) or ("synchronize swimming"))) or ("synchronized swimming"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((((("synchronised swimming") OR ("synchronizing swimming"))) OR ("synchronize swimming"))) OR ("synchronized swimming")).
• Removing quotes may allow a broader search: (((((( synchronised swimming ) or ( synchronizing swimming ))) or ( synchronize swimming ))) or ( synchronized swimming )).
• Adding a wildcard symbol may retrieve word variants: (((((("synchronised swimming") or ("synchronizing swimming"))) or ("synchronize swimming"))) or ("synchronized swimming"))*.