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