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