Perhaps you should try some spelling variations:
"artech does _ telecommunications service." » "artech does _ telecommunications services.", "artech does _ telecommunication services.", "artech does _ telecommunications provider.", "artech house _ telecommunications service."
"arten des mobile communication systems." » "arten does mobile communication systems.", "arten das mobile communication systems.", "arten less mobile communication systems.", "arten der mobile communication systems.", "akten des mobile communication systems.", "arten des mobile communication system."

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("artech does _ telecommunications service.") or ("arten des mobile communication systems."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("artech does _ telecommunications service.") OR ("arten des mobile communication systems.")).
• Removing quotes may allow a broader search: (( artech does _ telecommunications service. ) or ( arten des mobile communication systems. )).
• Adding a wildcard symbol may retrieve word variants: (("artech does _ telecommunications service.") or ("arten des mobile communication systems."))*.