Perhaps you should try some spelling variations:
22christian design » unchristian design, christian designed
design conclusions » design conclusion
ref history » reef history, brief history, bief history
21 germany » 2.1 germany, 11 germany, 2 germany
2021 20th » 2021 24th, 2020 20th, 2021 10th
2021 13th » 2021 6th, 2021 7th, 2021 5th

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: %22christian design conclusions %((21 germany) OR (7 germany)) %ref history %((2021 20th) OR (2021 13th)) century%22.
• Adding a wildcard symbol may retrieve word variants: %22christian design conclusions %((21 germany) or (7 germany)) %ref history %((2021 20th) or (2021 13th)) century%22*.