Perhaps you should try some spelling variations:
mittelbar » mittelbare, unmittelbar, unmittelbare
ermittelbar » ermittelbare, erunmittelbar, erunmittelbare, unmittelbar
unmittelbaree » unmittelbareee, ununmittelbaree, ununmittelbareee, unmittelbare, unmittelbaren, unmittelbarer
mittelbis » mittelbaus, mittelbau

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 mittelbis).
• Adding a wildcard symbol may retrieve word variants: ((mittelbar or (ermittelbar or unmittelbaree)) or mittelbis)*.