Perhaps you should try some spelling variations:
"central de research focus survey." » "central de research process survey.", "central de research forest survey.", "central de research force survey.", "central de research jobs survey.", "central does research focus survey.", "central key research focus survey.", "central led research focus survey.", "centrale des research focus survey.", "central _ research focus survey.", "centro de research focus survey."
"central city research _ series." » "central society research _ series.", "central equity research _ series.", "central cgiar research _ series.", "central cities research _ series."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("central city research _ series.") or ("central de research focus survey."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("central city research _ series.") OR ("central de research focus survey."))*.
• Removing quotes may allow a broader search: (( central city research _ series. ) or ( central de research focus survey. ))*.