Perhaps you should try some spelling variations:
mittelbar » unmittelbar, ermittelbar, unmittelbare
mittelbare » unmittelbare, ermittelbare, unmittelbaree, unmittelbaren
ermittelbare » erunmittelbare, erermittelbare, erunmittelbaree, erunmittelbaren, ermittelbar, unmittelbare, vermittelbar
unmittelbaree » ununmittelbaree, unermittelbaree, ununmittelbareee, ununmittelbarene, unmittelbare, unmittelbaren, unmittelbarer
unmittelbareee » ununmittelbareee, unermittelbareee, ununmittelbareeee, ununmittelbarenee, unmittelbaree, unmittelbarene, unmittelbarere, unmittelbareren, unmittelbare, unmittelbaren

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