Perhaps you should try some spelling variations:
"central asia research _ series." » "central basic research _ series.", "central cgiar research _ series.", "central a research _ series."
"central de research from surveys." » "central de research group surveys.", "central de research team surveys.", "central de research program surveys.", "central de research from survey.", "central de research firm surveys.", "central de research force surveys.", "central does research from surveys.", "central key research from surveys.", "central led research from surveys.", "centrale des research from surveys.", "central _ research from surveys.", "centro de research from surveys."

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

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