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