Perhaps you should try some spelling variations:
learning inequality » learning quality, measuring inequality, deepening inequality
holder's inequality » hardy's inequality
garding inequality » garding's inequality, hardy inequality, hardy's inequality
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 OR wave) AND ((((learning inequality) OR (garding inequality))) OR (((holder's inequality) OR (earnings inequality)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(wage or wave) and ((((learning inequality) OR (garding inequality))) or (((holder's inequality) or (earnings inequality))))".
• Adding a wildcard symbol may retrieve word variants: (wage or wave) and ((((learning inequality) OR (garding inequality))) or (((holder's inequality) or (earnings inequality))))*.