Perhaps you should try some spelling variations:
learning inequality » learning quality, garding inequality, measuring inequality
hardy's inequality » holder's inequality, harnack inequality
hardy 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 (((((hardy's inequality) OR (hardy inequality))) OR (earnings inequality)))).
• Adding a wildcard symbol may retrieve word variants: wage and ((learning inequality) or (((((hardy's inequality) or (hardy inequality))) or (earnings inequality))))*.