Perhaps you should try some spelling variations:
hieu luat » hieu qua
quang uan » quang tuan, quang ban, quang tran
kien soat » kiem soat, bien soan, kien hoa
luan can » luan van, luan san, luan han
can hieu » can nhieu, cao hieu, van hieu
van kien » van tien, van hien, van chien
uan van » luan van, quan 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 luan can hieu luat ) OR ( tinh quang uan van kien soat ))~.
• Adding a wildcard symbol may retrieve word variants: (( tin dung luan can hieu luat ) or ( tinh quang uan van kien soat ))*.