Perhaps you should try some spelling variations:
descriptions based » description based, descriptors based, descriptor based
descriptive based » description based, descriptive basis, descriptor based
descriptive case » descriptive clause, descriptive phase, description case

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: "\"((\\"((descriptive case) OR (descriptive based))\\") or (\\"descriptions based\\"))\"".
• Removing quotes may allow a broader search: (( ((descriptive case) OR (descriptive based)) ) or ( descriptions based )).