Perhaps you should try some spelling variations:
"central s.asi_ research team series." » "central basic research team series.", "central asia research team series.", "central s.a research team series.", "central s.asi_ research stem series.", "central s.asi_ research nejm series.", "central s.asi_ research tilsm series."
"central tax research firm surveys." » "central tax research from surveys.", "central tax research field surveys.", "central tax research final surveys.", "central 2 research firm surveys.", "central 2.1 research firm surveys.", "central 2.2 research firm surveys.", "central tax research firm survey.", "central taxes research firm surveys.", "central bank research firm 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 s.asi_ research team series.") or ("central tax research firm surveys."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("central s.asi_ research team series.") OR ("central tax research firm surveys."))*.
• Removing quotes may allow a broader search: (( central s.asi_ research team series. ) or ( central tax research firm surveys. ))*.