Perhaps you should try some spelling variations:
2.1 germany » 2017 germany, 9.13 germany, 9.14 germany
ref history » reef history, brief history, bief history
21 germany » 11 germany, 20 germany, 8 germany
2 germany » 2 german, 8 germany, 5 germany
20 20th » 2019 20th, 2020 20th, 2023 20th
90 20th » 94 20th, 1990 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 %((((21 germany) OR (2.1 germany))) OR (((2 germany) OR (7 germany)))) %ref history %((20 20th) OR (90 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 germany) or (7 germany)))) %ref history %((20 20th) OR (90 20th)) century%22".
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((((21 germany) or (2.1 germany))) or (((2 germany) or (7 germany)))) %ref history %((20 20th) OR (90 20th)) century%22*.