Perhaps you should try some spelling variations:
"trigger technik leitfaden" » "trigger methodik leitfaden", "triggers technical leitfaden"
"trigger mechanism leitfaden" » "trigger mechanisms leitfaden", "triggering mechanism leitfaden", "triggering mechanisms 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 ("trigger mechanism leitfaden")).
• Removing quotes may allow a broader search: (( trigger technik leitfaden ) or ( trigger mechanism leitfaden )).
• Adding a wildcard symbol may retrieve word variants: (("trigger technik leitfaden") or ("trigger mechanism leitfaden"))*.