Perhaps you should try some spelling variations:
"harvard world case studies book series." » "harvard cold case studies book series.", "harvard world class studies book series.", "harvard world case studies books series.", "harvard world case studies ebook series."
"harvard world's most studies book series." » "harvard cold's most studies book series.", "harvard world's cost studies book series.", "harvard world's east studies book series.", "harvard world's past studies book series.", "harvard world's most studies books series.", "harvard world's most studies ebook series."

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 case studies book series.") or ("harvard world's most studies book series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("harvard world case studies book series.") OR ("harvard world's most studies book series."))*.
• Removing quotes may allow a broader search: (( harvard world case studies book series. ) or ( harvard world's most studies book series. ))*.