Perhaps you should try some spelling variations:
communications automation » communications information, communications innovation, communications application
automation case » automation fast, automation a
case extension » base extension, casl extension, based extension
range spaces » gauge spaces, range states, large spaces
tuple spaces » tuple space, type spaces, triple space
large sparse » large scale

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

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