Perhaps you should try some spelling variations:
open conversations » agent conversations, roman conversations, content conversations
christian open » christian opened, christian open'd, christian popes
bief history » brief history, brief hystory, imf history
2.1 germany » 21 germany, 2017 germany, 9.13 germany
ref history » reef history, brief history, imf history
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: %christian open conversations %2.1 germany %((ref history) OR (bief history)) %2.2 18th century%22.
• Adding a wildcard symbol may retrieve word variants: %christian open conversations %2.1 germany %((ref history) or (bief history)) %2.2 18th century%22*.