Perhaps you should try some spelling variations:
"harvard second urban studies from sources." » "harvard second loan studies from sources.", "harvard second rural studies from sources.", "harvard second urban studies fuel sources.", "harvard second urban studies from survey."
"harvard world bank study from series." » "harvard world bank study from service.", "harvard world bank study from surveys.", "harvard world bank study from serbian."

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 study from series.") or ("harvard second urban studies from sources."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("harvard world bank study from series.") OR ("harvard second urban studies from sources."))*.
• Removing quotes may allow a broader search: (( harvard world bank study from series. ) or ( harvard second urban studies from sources. ))*.