Perhaps you should try some spelling variations:
"central american research project epi." » "central americans research project epi.", "central african research project epi.", "central numerical research project epi.", "central america research project epi.", "central american research project ep.", "central american research project e.", "central american research project ed."
"central de research project sri." » "central e research project sri.", "central dore research project sri.", "central mode research project sri.", "central de research project soil.", "central de research project svp.", "central de research project series.", "central _ research project sri.", "central body research project sri."

Try widening your search to All Fields.

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

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