Perhaps you should try some spelling variations:
wang yang » wang yan, wang liang, wang yanling
wong john » wrong john, kong john, longo john
tran hua » tan hua, tran duc
tuan hua » tan hua, tuan vu, yuan hui
ren wong » ren weng
bonn ana » bonn a, bonn auf, bonn und
bonn am » bonn a, bonn zum, bonn auf

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 ((tran hua) OR (tuan hua)) ren wong john ((bonn ana) OR (bonn am)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang yang ((tran hua) or (tuan hua)) ren wong john ((bonn ana) OR (bonn am)) ;~".
• Adding a wildcard symbol may retrieve word variants: wang yang ((tran hua) or (tuan hua)) ren wong john ((bonn ana) OR (bonn am)) ;*.