Perhaps you should try some spelling variations:
"harvard world class studies book series." » "harvard world cass studies book series.", "harvard world cases studies book series.", "harvard world css studies book series.", "harvard world class studies books series.", "harvard world class studies ebook series."
"harvard cold bank study fuel source." » "harvard world bank study fuel source.", "harvard bond bank study fuel source.", "harvard good bank study fuel source.", "harvard cold bank study fuel sources.", "harvard cold bank study fuel resource."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("harvard cold bank study fuel source.") or ("harvard world class studies book series."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("harvard cold bank study fuel source.") OR ("harvard world class studies book series."))*.
• Removing quotes may allow a broader search: (( harvard cold bank study fuel source. ) or ( harvard world class studies book series. ))*.