Perhaps you should try some spelling variations:
"synchronised swimming" » "synchronize swimming"
"synchronised stemming" » "synchronize stemming", "synchronised steering", "synchronised stepping", "synchronised stealing"
"synchronising stemming" » "synchronising steering", "synchronising stepping", "synchronising stealing", "synchronizing stemming", "synchronisations stemming"
"synchronized stemming" » "synchronized steering", "synchronized stepping", "synchronized stealing"
"synchronism stemming" » "synchronism steering", "synchronism stepping", "synchronism stealing", "synchronize stemming"
"synchronising flemming" » "synchronizing flemming", "synchronisations flemming", "synchronising fleming"
"synchronism streaming" » "synchronize streaming", "synchronism treating"

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