Perhaps you should try some spelling variations:
mittelbar » mittelbare, unmittelbar, ermittelbar
unmittelbare » unmittelbaree, ununmittelbare, unermittelbare, unmittelbar, ermittelbar
unermittelbare » unermittelbaree, unerunmittelbare, unerermittelbare, unvermittelbare, ermittelbare, vermittelbare
unmittelbaren » unmittelbareen, ununmittelbaren, unermittelbaren, unmittelbarn, ermittelbarn, unmittelbar
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 ((unmittelbare OR unermittelbare) OR unmittelbaren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((mittelbar or mittelbach) or ((unmittelbare OR unermittelbare) or unmittelbaren))".
• Adding a wildcard symbol may retrieve word variants: ((mittelbar or mittelbach) or ((unmittelbare OR unermittelbare) or unmittelbaren))*.