Perhaps you should try some spelling variations:
"central a research program synthesis." » "central a research programs synthesis.", "central _ research program synthesis.", "central 2 research program synthesis.", "central s.a research program synthesis.", "central de research program synthesis."
"central tax research project stress." » "central tax research projects stress.", "central tax research project success.", "central tax research project sites.", "central bank research project stress.", "central _ research project stress.", "central 2 research project stress.", "central taxes research project stress."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("central a research program synthesis.") or ("central tax research project stress."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("central a research program synthesis.") OR ("central tax research project stress.")).
• Removing quotes may allow a broader search: (( central a research program synthesis. ) or ( central tax research project stress. )).
• Adding a wildcard symbol may retrieve word variants: (("central a research program synthesis.") or ("central tax research project stress."))*.