Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
dung quan » dung quang, dung luan, luong quan
hieu soat » hieu hoat, hieu luat, hieu so
hieu suat » hieu luat, hieu qua
tinh dang » binh dang, tinh sang, dinh dang
dang quan » dang quang, nang quan, dan quan
kiem soat » kiem toan
quan cao » quang cao, quan cau, quan ao
quan van » luan van, quan va, quan luan
van kiem » va kiem, van kien, van hieu

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