Perhaps you should try some spelling variations:
bief history » brief hystory, imf history, ref history
reef history » reeves history, reef fishery, imf history
21 germany » 11 germany, 20 germany, 7 germany
2 germany » 7 germany, 2 german, 8 germany
20 18th » 2017 18th, 2021 18th, 2018 18th

Try widening your search to All Fields.

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 %((21 germany) OR (2 germany)) %((((bief history) OR (reef history))) OR (brief history)) %20 18th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((21 germany) or (2 germany)) %((((bief history) OR (reef history))) or (brief history)) %20 18th century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((21 germany) or (2 germany)) %((((bief history) OR (reef history))) or (brief history)) %20 18th century%22*.