Perhaps you should try some spelling variations:
mittelbar » mittelbare, unmittelbar
ermittelbare » ermittelbaree, erunmittelbare, mittelbare, vermittelbar, unmittelbaren, unmittelbare
ermittelbar » ermittelbare, erunmittelbar, unmittelbar
ermittelbaree » ermittelbareee, erunmittelbaree, mittelbaree, vermittelbare, unmittelbarene, unmittelbaree, ermittelbaren, ermittelbarkeit
unmittelbare » unmittelbaree, ununmittelbare, unmittelbar
mittelbach » mittelbare

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