Perhaps you should try some spelling variations:
"nijhoff book title 21" » "nijhoff boston title 21", "nijhoff book titles 21", "nijhoff ebook title 21", "nijhoff book table 21", "nijhoff book title 1", "nijhoff book title 2", "nijhoff book title _"
"nijhoff op title 26" » "nijhoff _ title 26", "nijhoff j title 26", "nijhoff sop title 26", "nijhoff shop title 26", "nijhoff app title 26", "nijhoff op title 2", "nijhoff op title 25", "nijhoff op title _"

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 op title 26") OR ("nijhoff book title 21"))*.
• Removing quotes may allow a broader search: (( nijhoff op title 26 ) or ( nijhoff book title 21 ))*.