Perhaps you should try some spelling variations:
learning inequality » earnings inequality, garding inequality, measuring inequality
learning disability » learning disabilities
learning ability » learning activity, learning about

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