Perhaps you should try some spelling variations:
communication concepts » communication circuits, communication congresses, communication channels
based extension » based extraction
concepts based » concept based, concepts cases, concepts case
range spaces » gauge spaces, range states, large spaces
phase spaces » phase space, shape spaces, state spaces
large sparse » large scale

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 concepts based extension ((((range spaces) OR (phase spaces))) OR (large sparse))~.
• Adding a wildcard symbol may retrieve word variants: communication concepts based extension ((((range spaces) or (phase spaces))) or (large sparse))*.