Perhaps you should try some spelling variations:
2f history » 2.1 history, imf history, etf history
20 germany » 2 germany, 7 germany, 8 germany
25 germany » 5 germany, 2 germany, 21 germany
2019 20th » 2019 4th, 2019 16th, 2019 7th
2019 6th » 2019 4th
2019 5th » 2019 4th
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 %((25 germany) OR (20 germany)) %2f history %((((((2019 20th) OR (2019 6th))) OR (2019 5th))) OR (90 20th)) century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((25 germany) or (20 germany)) %2f history %((((((2019 20th) OR (2019 6th))) or (2019 5th))) or (90 20th)) century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((25 germany) or (20 germany)) %2f history %((((((2019 20th) OR (2019 6th))) or (2019 5th))) or (90 20th)) century%22*.