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

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: (( tin dung lan van kien soat ) OR ( ((tinh quan) OR (tin quan)) va van hieu soat ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tin dung lan van kien soat ) or ( ((tinh quan) OR (tin quan)) va van hieu soat ))~".
• Adding a wildcard symbol may retrieve word variants: (( tin dung lan van kien soat ) or ( ((tinh quan) OR (tin quan)) va van hieu soat ))*.