Perhaps you should try some spelling variations:
communication conversion » communication conversation, communications convention, communication cohesion
conversion based » conversion del, conversion a, converter based
based extension » based extraction
large spaces » larger spaces, large scales, range spaces
gauge spaces » safe spaces, use spaces
large space » large sparse, large scale, large surface

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

• Performing a fuzzy search may retrieve terms with similar spellings: communication conversion based extension ((((large spaces) or (gauge spaces))) or (large space))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: communication conversion based extension ((((large spaces) OR (gauge spaces))) OR (large space)).
• Adding a wildcard symbol may retrieve word variants: communication conversion based extension ((((large spaces) or (gauge spaces))) or (large space))*.