Perhaps you should try some spelling variations:
serious conversation » curious conversations, serious conideration, versus conversation
22christian serious » christian sermons
reef history » brief history, reeves history, reef fishery
21 germany » 11 germany, 2 germany, 20 germany
2021 13th » 2021 6th, 2021 7th, 2021 5th
2.2 18th » 2021 18th, 2022 18th, 2023 18th

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 serious conversation %21 germany %reef history %((2.2 18th) OR (2021 13th)) century%22.
• Adding a wildcard symbol may retrieve word variants: %22christian serious conversation %21 germany %reef history %((2.2 18th) or (2021 13th)) century%22*.