Perhaps you should try some spelling variations:
communication concepts » communication circuits, communication congresses, communication channels
case divisions » class divisions, case decisions, course divisions
concepts case » concepts cases, concepts a, concepts chapter
sample spaces » sample space, sample speeches, sample sizes
tuple spaces » tuple space, type spaces, triple space
use spaces » phase spaces, gauge spaces, whose spaces

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

• Performing a fuzzy search may retrieve terms with similar spellings: communication concepts case divisions ((((use spaces) or (sample spaces))) or (tuple spaces))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communication concepts case divisions ((((use spaces) OR (sample spaces))) OR (tuple spaces)).
• Adding a wildcard symbol may retrieve word variants: communication concepts case divisions ((((use spaces) or (sample spaces))) or (tuple spaces))*.