Perhaps you should try some spelling variations:
ref history » reef history, brief history, bief history
imf history » brief history
2 germany » 12 germany, 7 germany, 6 germany
5 germany » 7 germany, 5 german, 6 germany
8 germany » 7 germany, 1918 germany
2 german » 3 german, 5 german

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: %22agriculture AND state %((((((2 germany) OR (2 german))) OR (5 germany))) OR (8 germany)) %((ref history) OR (imf history)) %2f 18th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((((((2 germany) OR (2 german))) or (5 germany))) or (8 germany)) %((ref history) or (imf history)) %2f 18th century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((((((2 germany) OR (2 german))) or (5 germany))) or (8 germany)) %((ref history) or (imf history)) %2f 18th century%22*.