Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
kien soat » kiem soat, bien soan, kien hoa
hieu soan » hieu toan, hieu van, bien soan
hieu suat » hieu luat, hieu qua
dung lan » dung luan, dung land, dung lam
van kien » van tien, van hien, van chien
lan van » luan van, lang van, tan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh dung lan van kien soat ) or ( tinh dung lan van ((hieu soan) OR (hieu suat)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung lan van kien soat ) OR ( tinh dung lan van ((hieu soan) OR (hieu suat)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung lan van kien soat ) or ( tinh dung lan van ((hieu soan) OR (hieu suat)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung lan van kien soat ) or ( tinh dung lan van ((hieu soan) OR (hieu suat)) ))*.