Perhaps you should try some spelling variations:
"harvard toll level studies book series." » "harvard toll legal studies book series.", "harvard toll event studies book series.", "harvard toll level studies from series.", "harvard tool level studies book series."
"harvard cold wave studies book series." » "harvard cold case studies book series.", "harvard cold cases studies book series.", "harvard cold bank studies book series.", "harvard cold wave studies from series.", "harvard cold water studies book series.", "harvard cold war studies book series."

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"harvard cold wave studies book series.\") OR (\"harvard toll level studies book series.\"))~".
• Removing quotes may allow a broader search: (( harvard cold wave studies book series. ) OR ( harvard toll level studies book series. ))~.
• Adding a wildcard symbol may retrieve word variants: (("harvard cold wave studies book series.") OR ("harvard toll level studies book series."))*.