Perhaps you should try some spelling variations:
efficient medication » efficient modification, efficient replication, efficient prediction
efficiency equation » efficiency education, efficiency evaluation, efficiency reduction
efficient education » efficient educational, efficiency education, efficient reduction

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: %((efficiency equation) OR (((efficient education) OR (efficient medication))))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((efficiency equation) or (((efficient education) OR (efficient medication))))%22".
• Adding a wildcard symbol may retrieve word variants: %((efficiency equation) or (((efficient education) OR (efficient medication))))%22*.