Perhaps you should try some spelling variations:
"trubner methodik leitfaden" » "trubner methodischer leitfaden", "uber methodik leitfaden", "einer methodik leitfaden", "grobner methods leitfaden"
"trigger technik leitfaden" » "trigger mechanism 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: (("trigger technik leitfaden") OR ("trubner methodik leitfaden")).
• Removing quotes may allow a broader search: (( trigger technik leitfaden ) or ( trubner methodik leitfaden )).
• Adding a wildcard symbol may retrieve word variants: (("trigger technik leitfaden") or ("trubner methodik leitfaden"))*.