Perhaps you should try some spelling variations:
mittelbar » unmittelbar, ermittelbar, unmittelbare
mittelbare » unmittelbare, ermittelbare, unmittelbaree, unmittelbaren
unmittelbaree » ununmittelbaree, unermittelbaree, ununmittelbareee, ununmittelbarene, unmittelbare, unmittelbaren, unmittelbarem
unmittelbarer » ununmittelbarer, unermittelbarer, ununmittelbareer, ununmittelbarenr, unmittelbare, unmittelbaren, unmittelbar
unmittelbareren » ununmittelbareren, unermittelbareren, ununmittelbareeren, ununmittelbarenren, unmittelbareen, unmittelbarenen, unmittelbaren, unmittelbarsten, unmittelbarkeiten

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 mittelbare) OR ((unmittelbaree OR unmittelbarer) OR unmittelbareren)).
• Adding a wildcard symbol may retrieve word variants: ((mittelbar or mittelbare) or ((unmittelbaree or unmittelbarer) or unmittelbareren))*.