Perhaps you should try some spelling variations:
spoken conversations » spoken conversation, open conversations, oboen conversations
upon conversations » union conversations, open conversations, human conversations
motets history » contents history, forests history, magnets history
motif history » motion history, motive history, motifs histone
20th century » 18th century
ref history » reef history, brief history, bief history
etf history » reef history, beruf history, ethis history
tnf history » stone history, reef history, bief history
imf history » brief history
2f germany » 2 germany, 20 germany, 21 germany
2f 20th » 20 20th, 2.2 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: %christianity ((upon conversations) OR (spoken conversations)) %2f germany %((((((((etf history) OR (tnf history))) OR (imf history))) OR (((motif history) OR (motets history))))) OR (ref history)) %2f 20th century%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%christianity ((upon conversations) or (spoken conversations)) %2f germany %((((((((etf history) or (tnf history))) or (imf history))) or (((motif history) OR (motets history))))) or (ref history)) %2f 20th century%22".
• Adding a wildcard symbol may retrieve word variants: %christianity ((upon conversations) or (spoken conversations)) %2f germany %((((((((etf history) or (tnf history))) or (imf history))) or (((motif history) OR (motets history))))) or (ref history)) %2f 20th century%22*.