Perhaps you should try some spelling variations:
"synchronised swimming" » "synchronize swimming", "synchronising swimming"
"synchronised stemming" » "synchronize stemming", "synchronising stemming", "synchronised steering", "synchronised flemming", "synchronised stepping"
"synchronised treating" » "synchronize treating", "synchronising treating", "synchronised creating", "synchronised heating", "synchronised relating"
"synchronism swimming" » "synchronize swimming", "synchronising 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 ("synchronism swimming"))) or ((("synchronised stemming") or ((("synchronized streaming") or ("synchronised treating"))))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("synchronised swimming") OR ("synchronism swimming"))) OR ((("synchronised stemming") OR ((("synchronized streaming") OR ("synchronised treating")))))).
• Removing quotes may allow a broader search: (((( synchronised swimming ) or ( synchronism swimming ))) or ((( synchronised stemming ) or ((( synchronized streaming ) or ( synchronised treating )))))).
• Adding a wildcard symbol may retrieve word variants: (((("synchronised swimming") or ("synchronism swimming"))) or ((("synchronised stemming") or ((("synchronized streaming") or ("synchronised treating"))))))*.