Perhaps you should try some spelling variations:
"artech house _ telecommunications service." » "artech house _ telecommunications services.", "artech house _ telecommunication services.", "artech house _ telecommunications provider."
"artech more mobile communication services." » "artech more mobile telecommunications services."

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 more mobile communication services.") or ("artech house _ telecommunications service."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("artech more mobile communication services.") OR ("artech house _ telecommunications service.")).
• Removing quotes may allow a broader search: (( artech more mobile communication services. ) or ( artech house _ telecommunications service. )).
• Adding a wildcard symbol may retrieve word variants: (("artech more mobile communication services.") or ("artech house _ telecommunications service."))*.