Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh huong
hieu suat » hieu luat, hieu qua
quang uan » quang tuan, quang ban, quang tran
kiem toan » ke toan, kiem tra
dung lan » dung luan, dung land, dung lam
van hieu » cao hieu
lan van » luan van, lang van, tan van
uan va » luan va, quan va, ban va

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