Perhaps you should try some spelling variations:
union conversations » win conversations, design conversations, driven conversations
2017 germany » 20 germany, 17 germany, 2006 germany
20th century » 18th century
ref history » reef history, brief history, bief history
21 germany » 11 germany, 2 germany, 20 germany
20 20th » 90 20th, 2019 20th, 2020 20th

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 ((union conversations) OR (((((design conclusions) OR (design conclusion))) OR (design construction)))) %((21 germany) OR (2017 germany)) %ref history %20 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22christian ((union conversations) or (((((design conclusions) OR (design conclusion))) or (design construction)))) %((21 germany) or (2017 germany)) %ref history %20 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %22christian ((union conversations) or (((((design conclusions) OR (design conclusion))) or (design construction)))) %((21 germany) or (2017 germany)) %ref history %20 20th century%22*.