Perhaps you should try some spelling variations:
invent conversations » content conversations, violent conversations, agent conversations
design conversations » design considerations, design construction, design conclusions
20th century » 18th century
2.1 germany » 21 germany, 2017 germany, 9.13 germany
ref history » reef history, brief history, bief history
20 germany » 7 germany, 8 germany, 5 germany
2 germany » 7 germany, 2 german, 8 germany
2f 20th » 20 20th, 2.2 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: %22christian ((invent conversations) OR (design conversations)) %((20 germany) OR (((2 germany) OR (2.1 germany)))) %ref history %2f 20th century%22.
• Adding a wildcard symbol may retrieve word variants: %22christian ((invent conversations) or (design conversations)) %((20 germany) or (((2 germany) or (2.1 germany)))) %ref history %2f 20th century%22*.