Perhaps you should try some spelling variations:
mittelbau » mittelbare, mittelbach
mittelbar » mittelbare, ermittelbar, unmittelbare
ermittelbare » ermittelbaree, erermittelbare, erunmittelbaree, ermittelbar, unmittelbare, mittelbare
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 ermittelbare)) OR unmittelbar).
• Adding a wildcard symbol may retrieve word variants: ((mittelbau or (mittelbar or ermittelbare)) or unmittelbar)*.