Perhaps you should try some spelling variations:
communication affection » communication affecting, communicating affection, communication effective
communication adhesion » communication cohesion, communication aggression, communication decision
relational database » relational databases
database optimising » databases optimizing, data optimising, database optimized
all relational » full relational, xml relational, all rational

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((communication adhesion) OR (communication affection)) all relational database optimising~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((communication adhesion) OR (communication affection)) all relational database optimising".
• Adding a wildcard symbol may retrieve word variants: ((communication adhesion) OR (communication affection)) all relational database optimising*.