Perhaps you should try some spelling variations:
mittelbar » mittelbare, unmittelbare
ermittelbar » ermittelbare, erunmittelbare, unmittelbare
unmittelbaree » unmittelbareee, ununmittelbareee, unmittelbare, unmittelbaren, unmittelbarer
unmittelbar » unmittelbare, ununmittelbare
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 (ermittelbar OR (unmittelbaree OR unmittelbar))) OR mittelbisau).
• Adding a wildcard symbol may retrieve word variants: ((mittelbar or (ermittelbar or (unmittelbaree or unmittelbar))) or mittelbisau)*.