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

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( fiber-((oral communication) OR (radar communication)) ) or ( fiber-((mobile communication) or (aided communication)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( fiber-((oral 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-((oral communication) OR (radar communication)) ) or ( fiber-((mobile communication) or (aided communication)) ))".
• Adding a wildcard symbol may retrieve word variants: (( fiber-((oral communication) OR (radar communication)) ) or ( fiber-((mobile communication) or (aided communication)) ))*.