Perhaps you should try some spelling variations:
20th century » 18th century
2f history » imf history, etf history, ref history
2 german » 3 german
5 german » 3 german
2.2 20th » 2020 20th, 2023 20th, 2021 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 (5 german)) %((2f history) OR (brief history)) %2.2 20th century%22.
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((2 german) or (5 german)) %((2f history) or (brief history)) %2.2 20th century%22*.