Perhaps you should try some spelling variations:
20th century » 18th century
2.1 germany » 2017 germany, 9.13 germany, 9.14 germany
imf history » brief history
ref history » reef history, brief history, bief history
21 germany » 11 germany, 2 germany, 20 germany
12 german » 2012 german
2020 20th » 2020 16th, 2020 2021, 2020 5th
2 german » 3 german, 5 german

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) OR (2.1 germany))) OR (((2 german) OR (12 german)))) %((imf history) OR (ref history)) %2020 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22agriculture and state %((((21 germany) OR (2.1 germany))) or (((2 german) or (12 german)))) %((imf history) or (ref history)) %2020 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((((21 germany) OR (2.1 germany))) or (((2 german) or (12 german)))) %((imf history) or (ref history)) %2020 20th century%22*.