Perhaps you should try some spelling variations:
reformen von » formen von, referaten von, reformen der
reform von » form von
david hong » david ng
wang yang » wang yan, wang liang, wang yanling
yang wang » yang yang, yan wang, yang guang
wang wei » zhang wei, wang zhi
tan » than

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: wang yang wang wei ((reformen von) OR (reform von)) david hong tan ;~.
• Adding a wildcard symbol may retrieve word variants: wang yang wang wei ((reformen von) or (reform von)) david hong tan ;*.