Perhaps you should try some spelling variations:
mittelbar » mittelbare, ermittelbar
unmittelbare » unmittelbaree, unermittelbare, ermittelbar
unmittelbar » unmittelbare, unermittelbar
unerermittelbar » unerermittelbare, unererermittelbar, unvermittelbar, unvermittelbare
unmittelbaren » unmittelbareen, unermittelbaren, ermittelbarn
mittelbisau » mittelbau, mittelbis

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: (((mittelbar OR unmittelbare) OR ((unmittelbar OR unerermittelbar) OR unmittelbaren)) OR mittelbisau).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((mittelbar OR unmittelbare) or ((unmittelbar or unerermittelbar) or unmittelbaren)) or mittelbisau)".
• Adding a wildcard symbol may retrieve word variants: (((mittelbar OR unmittelbare) or ((unmittelbar or unerermittelbar) or unmittelbaren)) or mittelbisau)*.