Perhaps you should try some spelling variations:
communication operator » communication educator, communication over, communication conversation
method dimension » methods dimension, metric dimension, method extension
operator method » operations methods, operative methods
state spaces » state space
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 operator method dimension ((((use spaces) or (state spaces))) or (tuple spaces))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communication operator method dimension ((((use spaces) OR (state spaces))) OR (tuple spaces)).
• Adding a wildcard symbol may retrieve word variants: communication operator method dimension ((((use spaces) or (state spaces))) or (tuple spaces))*.