Perhaps you should try some spelling variations:
mittelbar » ermittelbar, unmittelbare
ununmittelbare » ununermittelbare, unununmittelbaree, unmittelbare, unvermittelbare, unmittelbarer, unununmittelbare
unmittelbar » unermittelbar, ununmittelbare
mittelbare » ermittelbare, unmittelbaree, unmittelbare
unmittelbaren » unermittelbaren, ununmittelbareen, ununmittelbaren, unmittelbare

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: ((mittelbach OR ((mittelbar OR ((ununmittelbare OR unmittelbar) OR (ununmittelbare OR unmittelbar))) OR mittelbare)) OR unmittelbaren).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((mittelbach or ((mittelbar or ((ununmittelbare OR unmittelbar) or (ununmittelbare OR unmittelbar))) or mittelbare)) or unmittelbaren)".
• Adding a wildcard symbol may retrieve word variants: ((mittelbach or ((mittelbar or ((ununmittelbare OR unmittelbar) or (ununmittelbare OR unmittelbar))) or mittelbare)) or unmittelbaren)*.