Perhaps you should try some spelling variations:
referaten von » referat von, referat vom
reformen von » formen von, reform von, reformen der
liang wei » xiang wei, zhang wei, wang wei
wan wang » yan wang, wang yang, qian wang
wen wang » wei wang, chen wang, weng fang
david g » david a, david _, david k
g tan » _ tan, g van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((wan wang) or (wen wang)) liang wei ((referaten von) OR (reformen von)) david g tan ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wan wang) OR (wen wang)) liang wei ((referaten von) OR (reformen von)) david g tan ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wan wang) or (wen wang)) liang wei ((referaten von) OR (reformen von)) david g tan ;*".