Perhaps you should try some spelling variations:
measuring inequality » measuring quality
learning inequality » learning quality, deepening inequality, reducing inequality
garding inequality » garding's inequality, hardy's inequality, rising inequality
hardy inequality » hardy's inequality, hardy inequalities, harnack inequality
wage » wave
earnings » warning

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: wage AND ((((((learning inequality) OR (measuring inequality))) OR (earnings inequality))) OR (((garding inequality) OR (hardy inequality)))).
• Adding a wildcard symbol may retrieve word variants: wage and ((((((learning inequality) or (measuring inequality))) or (earnings inequality))) or (((garding inequality) or (hardy inequality))))*.