Perhaps you should try some spelling variations:
"trubner methodischer leitfaden" » "uber methodische leitfaden", "erster methodischer leitfaden", "neuer methodischer leitfaden"
"trubner technik leitfaden" » "trubner methodik leitfaden", "uber technik leitfaden", "trigger technik leitfaden"
"struktur technik leitfaden" » "struktur methodik leitfaden", "struktur technische leitfaden", "kultur 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 technik leitfaden"))) OR ("trubner methodischer leitfaden")).
• Removing quotes may allow a broader search: (((( trubner technik leitfaden ) or ( struktur technik leitfaden ))) or ( trubner methodischer leitfaden )).
• Adding a wildcard symbol may retrieve word variants: (((("trubner technik leitfaden") or ("struktur technik leitfaden"))) or ("trubner methodischer leitfaden"))*.