Perhaps you should try some spelling variations:
2f germany » 2 germany, 20 germany, 25 germany
21 germany » 2.1 germany, 11 germany, 2 germany
2f prussia » _ prussia, 2v russia, 2 russia
di prussia » _ prussia, his prussian

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: %22industries %((2f germany) OR (21 germany)) %((2f prussia) OR (di prussia))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22industries %((2f germany) OR (21 germany)) %((2f prussia) or (di prussia))%22".
• Adding a wildcard symbol may retrieve word variants: %22industries %((2f germany) OR (21 germany)) %((2f prussia) or (di prussia))%22*.