Perhaps you should try some spelling variations:
mittelbar » unmittelbar, ermittelbar
mittelbare » unmittelbare, ermittelbare, unmittelbaren
unmittelbare » ununmittelbare, unermittelbare, ununmittelbaren, unmittelbar, ermittelbar
vermittelbar » verunmittelbar, verermittelbar, ermittelbar, vermittelter, vermittelnder

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 ((unmittelbare OR vermittelbar) OR unmittelbare)).
• Adding a wildcard symbol may retrieve word variants: ((mittelbar or mittelbare) or ((unmittelbare or vermittelbar) or unmittelbare))*.