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

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