Perhaps you should try some spelling variations:
"Evidence-based synthesis problems" » "Evidence-based synthesis problem", "Evidence-acid synthesis problems"
"evidence-based synthesis properties" » "evidence-acid synthesis properties"
"evidence-based synthesis processing" » "evidence-acid synthesis processing"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("Evidence-based synthesis problems") OR ("evidence-based synthesis properties"))) OR ("evidence-based synthesis processing")).
• Removing quotes may allow a broader search: (((( Evidence-based synthesis problems ) or ( evidence-based synthesis properties ))) or ( evidence-based synthesis processing )).
• Adding a wildcard symbol may retrieve word variants: (((("Evidence-based synthesis problems") or ("evidence-based synthesis properties"))) or ("evidence-based synthesis processing"))*.