Perhaps you should try some spelling variations:
communication section » communication second, communication perception, communication education
databases optimizing » catalysis optimizing, analysis optimizing, data optimizing
summary dimensional » many dimensional
databases mining » database mining, databases finding, databases combining
section summary » selection summary, action summary, session summary

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: communication section summary dimensional ((databases optimizing) OR (databases mining))~.
• Adding a wildcard symbol may retrieve word variants: communication section summary dimensional ((databases optimizing) or (databases mining))*.