Perhaps you should try some spelling variations:
"uber methodik leitfaden" » "uber methodischer leitfaden", "leber methodik leitfaden", "der methodik leitfaden", "uber methoden leitfaden"
"trubner technik leitfaden" » "uber technik leitfaden", "trigger technik leitfaden", "struktur technik leitfaden"

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: (("trubner technik leitfaden") OR ("uber methodik leitfaden")).
• Removing quotes may allow a broader search: (( trubner technik leitfaden ) or ( uber methodik leitfaden )).
• Adding a wildcard symbol may retrieve word variants: (("trubner technik leitfaden") or ("uber methodik leitfaden"))*.