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