Perhaps you should try some spelling variations:
mittelbach » mittelbar
mittelbare » unmittelbare, unmittelbaren
unmittelbaree » ununmittelbaree, ununmittelbarene, unmittelbare, unmittelbaren, unmittelbarer
unununmittelbare » ununununmittelbare, ununununmittelbaren, bundesunmittelbare, unmittelbare, sachunmittelbare

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: ((unmittelbar OR mittelbach) OR (mittelbare OR (unmittelbaree OR unununmittelbare))).
• Adding a wildcard symbol may retrieve word variants: ((unmittelbar or mittelbach) or (mittelbare or (unmittelbaree or unununmittelbare)))*.