Perhaps you should try some spelling variations:
mittelbar » mittelbare, unmittelbar, ermittelbar
unmittelbare » unmittelbaree, ununmittelbare, unermittelbare, unmittelbar, ermittelbar
unermittelbare » unermittelbaree, unerunmittelbare, unerermittelbare, unvermittelbare, ermittelbare, vermittelbare
unununmittelbareee » unununmittelbareeee, ununununmittelbareee, unununermittelbareee, unununmittelbaree, ununermittelbaree
unmittelbareeer » unmittelbareeeer, ununmittelbareeer, unermittelbareeer, unmittelbareer, ermittelbareer, unmittelbarer, unmittelbaren, unmittelbarkeit
mittelbis » mittelbaus, mittelbau

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 ((unmittelbare OR unermittelbare) OR (unununmittelbareee OR unmittelbareeer))) OR mittelbis).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((mittelbar or ((unmittelbare OR unermittelbare) or (unununmittelbareee or unmittelbareeer))) or mittelbis)".
• Adding a wildcard symbol may retrieve word variants: ((mittelbar or ((unmittelbare OR unermittelbare) or (unununmittelbareee or unmittelbareeer))) or mittelbis)*.