Perhaps you should try some spelling variations:
21 germany » 11 germany, 2 germany, 20 germany
2 german » 3 german, 5 german
2f 20th » 2.2 20th
20 20th » 2019 20th, 2020 20th, 2023 20th
90 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 %((2 german) OR (21 germany)) %((imf history) OR (brief history)) %((2f 20th) OR (((20 20th) OR (90 20th)))) century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((2 german) or (21 germany)) %((imf history) OR (brief history)) %((2f 20th) or (((20 20th) or (90 20th)))) century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((2 german) or (21 germany)) %((imf history) OR (brief history)) %((2f 20th) or (((20 20th) or (90 20th)))) century%22*.