Perhaps you should try some spelling variations:
mobile communication » risk communication
optic communication » optical communications, grid communication, oral communication
radar communication » railway communication, today communications, risk communication
aided communication » risk communication

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: (( fiber-((optic communication) OR (radar communication)) ) OR ( fiber-((mobile communication) OR (aided communication)) ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( fiber-((optic communication) or (radar communication)) ) or ( fiber-((mobile communication) OR (aided communication)) ))~".
• Adding a wildcard symbol may retrieve word variants: (( fiber-((optic communication) or (radar communication)) ) or ( fiber-((mobile communication) OR (aided communication)) ))*.