Perhaps you should try some spelling variations:
"synchronised swimming" » "synchronized swimming", "synchronize swimming", "synchronised stemming"
"synchronised treating" » "synchronized treating", "synchronize treating", "synchronised creating", "synchronised heating", "synchronised relating"
"synchronising swimming" » "synchronising stemming", "synchronizing swimming", "synchronisations swimming"
"synchronism steering" » "synchronize steering", "synchronized steering"

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 ((("synchronised treating") or ("synchronism steering"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("synchronised swimming") OR ("synchronising swimming"))) OR ((("synchronised treating") OR ("synchronism steering")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"synchronised swimming\") OR (\"synchronising swimming\"))) or (((\"synchronised treating\") or (\"synchronism steering\"))))".
• Removing quotes may allow a broader search: (((( synchronised swimming ) OR ( synchronising swimming ))) or ((( synchronised treating ) or ( synchronism steering )))).
• Adding a wildcard symbol may retrieve word variants: (((("synchronised swimming") OR ("synchronising swimming"))) or ((("synchronised treating") or ("synchronism steering"))))*.