Perhaps you should try some spelling variations:
"radio / appareils et materielle / guides, manuels, etc" » "radio / appareils der materielle / guides, manuels, etc", "radio / appareils et materiel / guides, manuels, etc", "radio / appareils 4 materielle / guides, manuels, etc"
"radio / appareils du materielle / guides, manuels, etc" » "radio / appareils d materielle / guides, manuels, etc", "radio / appareils die materielle / guides, manuels, etc", "radio / appareils das materielle / guides, manuels, etc", "radio / appareils de materielle / guides, manuels, etc", "radio / apparails de materielle / guides, manuels, etc", "radio / appareils a materielle / guides, manuels, etc"

Try widening your search to All Fields.

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: (("radio / appareils et materielle / guides, manuels, etc") OR ("radio / appareils du materielle / guides, manuels, etc")).
• Removing quotes may allow a broader search: (( radio / appareils et materielle / guides, manuels, etc ) or ( radio / appareils du materielle / guides, manuels, etc )).
• Adding a wildcard symbol may retrieve word variants: (("radio / appareils et materielle / guides, manuels, etc") or ("radio / appareils du materielle / guides, manuels, etc"))*.