Perhaps you should try some spelling variations:
ref history » reef history, brief history, bief history
25 germany » 5 germany, 2 germany, 21 germany
20 germany » 2 germany, 7 germany, 5 germany
8 germany » 7 germany, 1918 germany
2019 5th » 2019 4th, 2019 6th
90 20th » 20 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 %((25 germany) OR (((20 germany) OR (8 germany)))) %ref history %((2019 5th) OR (90 20th)) century%22.
• Adding a wildcard symbol may retrieve word variants: %22agriculture and state %((25 germany) or (((20 germany) or (8 germany)))) %ref history %((2019 5th) or (90 20th)) century%22*.