Perhaps you should try some spelling variations:
"synchronised swimming" » "synchronize swimming", "synchronising swimming", "synchronised stemming"
"synchronised steering" » "synchronize steering", "synchronising steering"
"synchronism swimming" » "synchronism stemming", "synchronize swimming", "synchronising swimming"
"synchronized swimming" » "synchronized stemming"

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 ("synchronized swimming"))))) or ("synchronised steering"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("synchronised swimming") OR ((("synchronism swimming") OR ("synchronized swimming"))))) OR ("synchronised steering")).
• Removing quotes may allow a broader search: (((( synchronised swimming ) or ((( synchronism swimming ) or ( synchronized swimming ))))) or ( synchronised steering )).
• Adding a wildcard symbol may retrieve word variants: (((("synchronised swimming") or ((("synchronism swimming") or ("synchronized swimming"))))) or ("synchronised steering"))*.