Perhaps you should try some spelling variations:
quang tran » quang tuan, quang trung, quang thanh
quang chan » quang thanh, quang khanh, quang khang
dung quan » dung quang, dung luan, luong quan
hieu luat » hieu qua
kien soat » kiem soat, bien soan, kien hoa
quan van » luan van, quan va, quan luan
van hieu » cao hieu
van kien » van tien, van hien, van chien

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 quan van hieu luat ) OR ( tinh ((quang chan) OR (quang tran)) van kien soat ))~.
• Adding a wildcard symbol may retrieve word variants: (( tin dung quan van hieu luat ) or ( tinh ((quang chan) or (quang tran)) van kien soat ))*.