Perhaps you should try some spelling variations:
communications circuits » communication circuits, communications concepts
controls dimension » control dimension, controlling dimension, countries dimensions
circuits controls » circuits control, circuit control, circus control
whose spaces » phase spaces, shape spaces, whose race
type spaces » state spaces
safe spaces » state spaces, shape spaces, scale spaces

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

• Performing a fuzzy search may retrieve terms with similar spellings: communications circuits controls dimension ((type spaces) or (((safe spaces) or (whose spaces))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communications circuits controls dimension ((type spaces) OR (((safe spaces) OR (whose spaces)))).
• Adding a wildcard symbol may retrieve word variants: communications circuits controls dimension ((type spaces) or (((safe spaces) or (whose spaces))))*.