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

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

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