Perhaps you should try some spelling variations:
ref history » reef history, brief history, bief history
imf history » brief history
21 germany » 2 germany, 20 germany, 7 germany
11 germany » 11 german, 1918 germany, 7 germany
2f history » etf history, tnf history, 7 history
2.2 20th » 2020 20th, 2023 20th, 2021 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 (11 germany)) %((((2f history) OR (ref history))) OR (imf history)) %((2.2 20th) OR (((2020 5th) OR (2020 16th)))) century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((21 germany) or (11 germany)) %((((2f history) or (ref history))) or (imf history)) %((2.2 20th) or (((2020 5th) OR (2020 16th)))) century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((21 germany) or (11 germany)) %((((2f history) or (ref history))) or (imf history)) %((2.2 20th) or (((2020 5th) OR (2020 16th)))) century%22*.