Perhaps you should try some spelling variations:
trinh san » trinh han, trinh quan, trinh toan
hieu suat » hieu qua
hieu luat » hieu qua
dung lang » dung dang, dung nang, dung land
kien soat » kiem soat, bien soan, kien hoa
san hang » san chang, ban hang, van hang
lang van » dang van, tang van, hoang van
van kien » van tien, van hien, van chien

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( trinh san hang va ((hieu suat) or (hieu luat)) ) or ( tin dung lang van kien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh san hang va ((hieu suat) OR (hieu luat)) ) OR ( tin dung lang van kien soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh san hang va ((hieu suat) or (hieu luat)) ) or ( tin dung lang van kien soat ))*.