Perhaps you should try some spelling variations:
20th century » 18th century
2.1 germany » 2017 germany, 9.13 germany, 9.14 germany
21 germany » 11 germany, 20 germany, 25 germany
2 germany » 12 germany, 2 german, 8 germany
2020 20th » 2020 16th, 2020 5th, 2020 2021

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 %((7 germany) OR (((((21 germany) OR (2.1 germany))) OR (2 germany)))) %brief history %2020 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((7 germany) or (((((21 germany) OR (2.1 germany))) or (2 germany)))) %brief history %2020 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((7 germany) or (((((21 germany) OR (2.1 germany))) or (2 germany)))) %brief history %2020 20th century%22*.