Perhaps you should try some spelling variations:
communication relations » communication relational, communication relating, communications regulations
based discussion » brief discussion
relations based » relation based, relations case, relations cases
array ang » arrays ang, array along, array range
arrays a » arrays _

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

• Performing a fuzzy search may retrieve terms with similar spellings: communication relations based discussion ((array ang) or (arrays a))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communication relations based discussion ((array ang) OR (arrays a)).
• Adding a wildcard symbol may retrieve word variants: communication relations based discussion ((array ang) or (arrays a))*.