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