Perhaps you should try some spelling variations:
learning inequality » earnings inequality, learning quality, measuring inequality
warning inequality » earnings inequality, widening inequality, facing inequality
garding inequality » garding's inequality, earnings inequality, hardy inequality
hardy's inequality » hardy inequality, holder's inequality, harnack inequality
wage » wave

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 (warning inequality))) OR (((garding inequality) OR (hardy's inequality)))).
• Adding a wildcard symbol may retrieve word variants: wage and ((((learning inequality) or (warning inequality))) or (((garding inequality) or (hardy's inequality))))*.