Perhaps you should try some spelling variations:
20th century » 18th century
2.1 germany » 21 germany, 2017 germany, 9.13 germany
ref history » reef history, brief history, bief history
11 germany » 11 german, 1918 germany, 8 germany
2 germany » 12 germany, 2 german, 8 germany
20 20th » 90 20th, 2019 20th, 2020 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 %((((11 germany) OR (2.1 germany))) OR (((2 germany) OR (7 germany)))) %ref history %20 20th century%22.
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((((11 germany) or (2.1 germany))) or (((2 germany) or (7 germany)))) %ref history %20 20th century%22*.