Perhaps you should try some spelling variations:
song ming » song bing, song min, gong min
juan rene » juan meng, juan rana
yan minh » tuan minh, sang minh, yang mind
cong van » congo can, duong van, cong sun
yuan zi » yuan li, yuan fei, yuan hui
yan zi » yan zhi, ban zi
wang » wing, wan, lang

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 ((yan zi) OR (yuan zi)) juan rene ((yan minh) OR (song ming)) cong van ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wang ((yan zi) OR (yuan zi)) juan rene ((yan minh) or (song ming)) cong van ;~".
• Adding a wildcard symbol may retrieve word variants: wang ((yan zi) OR (yuan zi)) juan rene ((yan minh) or (song ming)) cong van ;*.