Perhaps you should try some spelling variations:
communication concepts » communication circuits, communication congresses, communication channels
sources divisions » resources division, course divisions, sources vision
concepts sources » concepts series
gauge spaces » large space, safe spaces, use spaces
state spaces » state space
tuple spaces » tuple space, type spaces, triple space

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 sources divisions ((((gauge spaces) or (state spaces))) or (tuple spaces))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communication concepts sources divisions ((((gauge spaces) OR (state spaces))) OR (tuple spaces)).
• Adding a wildcard symbol may retrieve word variants: communication concepts sources divisions ((((gauge spaces) or (state spaces))) or (tuple spaces))*.