Perhaps you should try some spelling variations:
"synchronism swimming" » "synchronize swimming", "synchronising swimming"
"synchronisations swimming" » "synchronisation swimming", "synchronizations swimming", "synchronization swimming"
"synchronised 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: (((("synchronism swimming") or ("synchronisations swimming"))) or ((("synchronised stemming") or ("synchronized stemming"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("synchronism swimming") OR ("synchronisations swimming"))) OR ((("synchronised stemming") OR ("synchronized stemming")))).
• Removing quotes may allow a broader search: (((( synchronism swimming ) or ( synchronisations swimming ))) or ((( synchronised stemming ) or ( synchronized stemming )))).
• Adding a wildcard symbol may retrieve word variants: (((("synchronism swimming") or ("synchronisations swimming"))) or ((("synchronised stemming") or ("synchronized stemming"))))*.