Perhaps you should try some spelling variations:
"harvard world bank studies from surveys." » "harvard cold bank studies from surveys.", "harvard world urban studies from surveys.", "harvard world bank study from surveys.", "harvard world bank studies from survey.", "harvard world bank studies firm surveys.", "harvard world bank studies force surveys."
"harvard world bank studies pre surveys." » "harvard cold bank studies pre surveys.", "harvard world urban studies pre surveys.", "harvard world bank study pre surveys.", "harvard world bank studies part surveys.", "harvard world bank studies pt surveys.", "harvard world bank studies die surveys.", "harvard world bank studies pre survey.", "harvard world bank studies re surveys.", "harvard world bank studies tie surveys."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("harvard world bank studies from surveys.") or ("harvard world bank studies pre surveys."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("harvard world bank studies from surveys.") OR ("harvard world bank studies pre surveys.")).
• Removing quotes may allow a broader search: (( harvard world bank studies from surveys. ) or ( harvard world bank studies pre surveys. )).
• Adding a wildcard symbol may retrieve word variants: (("harvard world bank studies from surveys.") or ("harvard world bank studies pre surveys."))*.