Talvez debería tentar con algunhas variantes ortográficas:
communication activation » communication motivation, communication activities, communication mitigation
activation safety » aviation safety, estimation safety, activation set
spaces » dspaces
dspaces » ddspaces
ddspaces » dddspaces
space » dspace

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

• If you are trying to use Boolean operators, they must be ALL CAPS: communication activation safety (((spaces OR dspaces) OR dspaces) OR ddspaces) euclidean space~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "communication activation safety (((spaces OR dspaces) or dspaces) or ddspaces) euclidean space~".
• Adding a wildcard symbol may retrieve word variants: communication activation safety (((spaces OR dspaces) or dspaces) or ddspaces) euclidean space*.