Perhaps you should try some spelling variations:
warning inequality » earnings inequality, learning inequality, widening inequality
garding inequality » garding's inequality, earnings inequality, hardy's inequality
hardy inequality » hardy's inequality, hardy inequalities, harnack inequality

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 ((warning inequality) OR (((garding inequality) OR (hardy inequality)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(wage or wave) and ((warning inequality) or (((garding inequality) OR (hardy inequality))))".
• Adding a wildcard symbol may retrieve word variants: (wage or wave) and ((warning inequality) or (((garding inequality) OR (hardy inequality))))*.