Perhaps you should try some spelling variations:
"nijhoff book titles 26" » "nijhoff boston titles 26", "nijhoff op titles 26", "nijhoff book entitled 26", "nijhoff book intitled 26", "nijhoff book titles _", "nijhoff book titles 1", "nijhoff book titles ii"
"nijhoff book titles 2.9" » "nijhoff boston titles 2.9", "nijhoff op titles 2.9", "nijhoff book entitled 2.9", "nijhoff book intitled 2.9", "nijhoff book titles 19", "nijhoff book titles 3.1", "nijhoff book titles 3.2"
"nijhoff ebook title 20" » "nijhoff book title 20", "nijhoff ebook title 2", "nijhoff ebook title 10", "nijhoff ebook title 21"

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 book titles 26") OR ("nijhoff book titles 2.9"))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nijhoff ebook title 20\") or (((\"nijhoff book titles 26\") OR (\"nijhoff book titles 2.9\"))))*".
• Removing quotes may allow a broader search: (( nijhoff ebook title 20 ) or ((( nijhoff book titles 26 ) OR ( nijhoff book titles 2.9 ))))*.