Perhaps you should try some spelling variations:
descriptions based » descriptors based, descriptor based, descriptions chapter
description based » descriptor based, description des
descriptive case » descriptive clause, descriptive based, descriptive phase
descriptions a » descriptions _

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: "((\"descriptive case\") or (\"((((descriptions based) OR (descriptions a))) OR (description based))\"))".
• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((\\"descriptive case\\") or (\\"((((descriptions based) OR (descriptions a))) or (description based))\\"))\"".
• Removing quotes may allow a broader search: (( descriptive case ) or ( ((((descriptions based) OR (descriptions a))) or (description based)) )).