Perhaps you should try some spelling variations:
"struktur methodik leitfaden" » "struktur methodischer leitfaden", "strukturen methoden leitfaden", "sektor methodik 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 ("struktur methodik leitfaden")).
• Removing quotes may allow a broader search: (( trubner technik leitfaden ) or ( struktur methodik leitfaden )).
• Adding a wildcard symbol may retrieve word variants: (("trubner technik leitfaden") or ("struktur methodik leitfaden"))*.