Perhaps you should try some spelling variations:
"nijhoff ebook title 20" » "nijhoff book title 20", "nijhoff book titles 20", "nijhoff ebook title 21", "nijhoff ebook title 25", "nijhoff ebook title 26", "nijhoff ebook title a0", "nijhoff ebook title 10", "nijhoff ebook title he0"
"nijhoff ebook title 10" » "nijhoff book title 10", "nijhoff book titles 10", "nijhoff ebook title 1", "nijhoff ebook title a", "nijhoff ebook title he"
"nijhoff ebook title 2" » "nijhoff book title 2", "nijhoff book titles 2", "nijhoff ebook title a", "nijhoff ebook title 1", "nijhoff ebook title he"
"nijhoff ebook title _" » "nijhoff book title _", "nijhoff book titles _"

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 20") OR ("nijhoff ebook title 10"))) OR ("nijhoff ebook title 2"))) OR ("nijhoff ebook title _")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((\"nijhoff ebook title 20\") OR (\"nijhoff ebook title 10\"))) or (\"nijhoff ebook title 2\"))) or (\"nijhoff ebook title _\"))".
• Removing quotes may allow a broader search: (((((( nijhoff ebook title 20 ) OR ( nijhoff ebook title 10 ))) or ( nijhoff ebook title 2 ))) or ( nijhoff ebook title _ )).
• Adding a wildcard symbol may retrieve word variants: (((((("nijhoff ebook title 20") OR ("nijhoff ebook title 10"))) or ("nijhoff ebook title 2"))) or ("nijhoff ebook title _"))*.