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 streaming" » "synchronize streaming", "synchronising streaming", "synchronised treating"
"synchronism swimming" » "synchronize swimming", "synchronising swimming"

You may be able to get more results by adjusting your search query.

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