Perhaps you should try some spelling variations:
20th century » 18th century
21 germany » 11 germany, 20 germany, 8 germany
2 germany » 2 german, 8 germany, 5 germany
20 20th » 90 20th, 2019 20th, 2020 20th

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture AND state %((7 germany) OR (((21 germany) OR (2 germany)))) %((imf history) OR (brief history)) %20 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture AND state %((7 germany) OR (((21 germany) OR (2 germany)))) %((imf history) OR (brief history)) %20 20th century%22*.