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