Perhaps you should try some spelling variations:
communication documentation » communication communication, communication conversation
communication foundation » communication education, communication communication, communication information
based extension » based extraction
extension dehn » extension data, extension region, extension method
dehn viveros » de vivero, de viveres

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

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