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

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