Perhaps you should try some spelling variations:
mittelbau » mittelbare, mittelbach
mittelbar » mittelbare, ermittelbar, unmittelbare
erermittelbare » erermittelbaree, ererermittelbare, ererunmittelbaree, ermittelbare, vermittelbare, unvermittelbare
unmittelbar » unmittelbare, unermittelbar, ununmittelbare

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: ((mittelbau OR (mittelbar OR erermittelbare)) OR unmittelbar).
• Adding a wildcard symbol may retrieve word variants: ((mittelbau or (mittelbar or erermittelbare)) or unmittelbar)*.