Perhaps you should try some spelling variations:
die reformen » die reform, die formen, der reformen
reformen von » formen von, reform von, referaten von
von david » john david, ben david, jan david
zhang zhi » zhong zhi, wang zhi, zhang wei
you zhen » you when, you her, you zhi
you hear » you eat, you lead, you leap

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: warn ((you zhen) OR (you hear)) die reformen von david zhang zhi ;~.
• Adding a wildcard symbol may retrieve word variants: warn ((you zhen) or (you hear)) die reformen von david zhang zhi ;*.