Perhaps you should try some spelling variations:
private collections » private corporations
20 bibliography » 10 bibliography, 22 bibliography, 23 bibliography
1 bibliography » 11 bibliography, 12 bibliography, 13 bibliography
21 germany » 2.1 germany, 11 germany, 2 germany
2 private » 3 private, 5 private, 7 private
29 berlin » 21 berlin, 99 berlin, 39 berlin
2 berlin » _ berlin, 1 berlin, a berlin

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: %22humanities %((20 bibliography) OR (1 bibliography)) %2 private collections %21 germany %((29 berlin) OR (2 berlin)) %art catalogs%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22humanities %((20 bibliography) or (1 bibliography)) %2 private collections %21 germany %((29 berlin) OR (2 berlin)) %art catalogs%22".
• Adding a wildcard symbol may retrieve word variants: %22humanities %((20 bibliography) or (1 bibliography)) %2 private collections %21 germany %((29 berlin) OR (2 berlin)) %art catalogs%22*.