Perhaps you should try some spelling variations:
mittelbar » mittelbare, ermittelbar, unmittelbare
unmittelbaree » unmittelbareee, unermittelbaree, ununmittelbareee, unmittelbare, unmittelbaren, unmittelbarer
unmittelbareen » unmittelbareeen, unermittelbareen, ununmittelbareeen, unmittelbaren, unmittelbarenn, unmittelbarern, unmittelbareren, unmittelbarsten
unmittelbar » unmittelbare, unermittelbar, ununmittelbare
mittelbach » mittelbare

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 mittelbach) OR (unmittelbaree OR (unmittelbareen OR unmittelbar))).
• Adding a wildcard symbol may retrieve word variants: ((mittelbar or mittelbach) or (unmittelbaree or (unmittelbareen or unmittelbar)))*.