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

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