Perhaps you should try some spelling variations:
"harvard world war studies book series." » "harvard world war stories book series.", "harvard world early studies book series.", "harvard world war studies books series.", "harvard world war studies ebook series."
"harvard cold case studies book series." » "harvard world case studies book series.", "harvard cold call studies book series.", "harvard cold wave studies book series.", "harvard cold case studies books series.", "harvard cold case studies ebook series."

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("harvard cold case studies book series.") OR ("harvard world war studies book series."))~.
• Removing quotes may allow a broader search: (( harvard cold case studies book series. ) or ( harvard world war studies book series. ))~.
• Adding a wildcard symbol may retrieve word variants: (("harvard cold case studies book series.") or ("harvard world war studies book series."))*.