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

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

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