Perhaps you should try some spelling variations:
"harvard world bank studies from sources." » "harvard world urban studies from sources.", "harvard world bank study from sources.", "harvard world bank studies fuel sources.", "harvard world bank studies from survey."
"harvard worse case studies book series." » "harvard worst case studies book series.", "harvard worker case studies book series.", "harvard world case studies book series."

Try widening your search to All Fields.

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

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