Perhaps you should try some spelling variations:
"nijhoff ebook title a" » "nijhoff book title a", "nijhoff book titles a", "nijhoff ebook title _"
"nijhoff ebook title 5" » "nijhoff book title 5", "nijhoff book titles 5", "nijhoff ebook title _", "nijhoff ebook title 2", "nijhoff ebook title 4"
"nijhoff ebook title 1" » "nijhoff book title 1", "nijhoff book titles 1", "nijhoff ebook title _", "nijhoff ebook title 2"

Try widening your search to All Fields.

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: (("nijhoff ebook title a") OR ((("nijhoff ebook title 5") OR ("nijhoff ebook title 1")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nijhoff ebook title a\") or (((\"nijhoff ebook title 5\") OR (\"nijhoff ebook title 1\"))))".
• Removing quotes may allow a broader search: (( nijhoff ebook title a ) or ((( nijhoff ebook title 5 ) OR ( nijhoff ebook title 1 )))).
• Adding a wildcard symbol may retrieve word variants: (("nijhoff ebook title a") or ((("nijhoff ebook title 5") OR ("nijhoff ebook title 1"))))*.