Perhaps you should try some spelling variations:
quang quan » quang tuan, quang uan, quang xuan
tinh dung » trinh dung, tin dung, tinh quang
hieu suat » hieu luat, hieu qua
quan quan » quan quang, qua quan, quan luan
kiem soat » kiem toan
van kiem » va kiem, van kien, van hieu
luan va » luan van, luat va
va hieu » van hieu, va dieu, va hien

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