Perhaps you should try some spelling variations:
"synchronised swimming" » "synchronized swimming", "synchronism swimming", "synchronised stemming"
"synchronising swimming" » "synchronising stemming", "synchronism swimming"
"synchronisations swimming" » "synchronisations stemming", "synchronisation swimming", "synchronizations swimming", "synchronization swimming"
"synchronize swimming" » "synchronize stemming", "synchronized swimming", "synchronism swimming"
"synchronizing swimming" » "synchronizing stemming", "synchronized 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 ((("synchronising swimming") or ("synchronisations swimming"))))) or ((("synchronize swimming") OR ("synchronizing swimming"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("synchronised swimming") OR ((("synchronising swimming") OR ("synchronisations swimming"))))) OR ((("synchronize swimming") OR ("synchronizing swimming"))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"synchronised swimming\") or (((\"synchronising swimming\") or (\"synchronisations swimming\"))))) or (((\"synchronize swimming\") OR (\"synchronizing swimming\"))))*".
• Removing quotes may allow a broader search: (((( synchronised swimming ) or ((( synchronising swimming ) or ( synchronisations swimming ))))) or ((( synchronize swimming ) OR ( synchronizing swimming ))))*.