Perhaps you should try some spelling variations:
21 germany » 2.1 germany, 11 germany, 2 germany
2f history » imf history, etf history, ref history
1994 20th » 1995 20th, 1990 20th, 1994 10th
20 20th » 2019 20th, 2020 20th, 2023 20th
90 20th » 1990 20th
94 20th » 4 20th, 94 24th

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 %2f history %((20 20th) OR (((90 20th) OR (((94 20th) OR (1994 20th)))))) century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %21 germany %2f history %((20 20th) or (((90 20th) or (((94 20th) OR (1994 20th)))))) century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %21 germany %2f history %((20 20th) or (((90 20th) or (((94 20th) OR (1994 20th)))))) century%22*.