Perhaps you should try some spelling variations:
oboen conversations » open conversations, spoken conversations, bot conversations
spoken conversation » spoken conversations, open conversation, sponsor conversation
reef history » brief history, reeves history, reef fishery
20th century » 18th century
2.1 germany » 21 germany, 2017 germany, 9.13 germany
imf history » brief history
2.2 20th » 2020 20th, 2023 20th, 2021 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: %christian ((oboen conversations) OR (spoken conversation)) %2.1 germany %((reef history) OR (imf history)) %2.2 20th century%22.
• Adding a wildcard symbol may retrieve word variants: %christian ((oboen conversations) or (spoken conversation)) %2.1 germany %((reef history) or (imf history)) %2.2 20th century%22*.