Perhaps you should try some spelling variations:
reef history » brief history, reeves history, reef fishery
20th century » 18th century
1918 germany » 8 germany
2.1 germany » 2017 germany, 9.13 germany, 9.14 germany
etf history » imf history, ref history, tnf history
21 germany » 11 germany, 2 germany, 20 germany
11 german » 1 german
90 20th » 20 20th, 94 20th, 1990 20th

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 (2.1 germany))) OR (((11 german) OR (1918 germany)))) %((etf history) OR (reef history)) %90 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((((21 germany) OR (2.1 germany))) or (((11 german) or (1918 germany)))) %((etf history) or (reef history)) %90 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((((21 germany) OR (2.1 germany))) or (((11 german) or (1918 germany)))) %((etf history) or (reef history)) %90 20th century%22*.