Perhaps you should try some spelling variations:
duong quan » duong quang, duong qua, luong quan
tinh dung » trinh dung, tin dung, tinh quang
hieu soat » hieu hoat, hieu luat, hieu so
hieu suat » hieu luat, hieu qua
kiem soat » kiem toan
dung lan » dung luan, dung land, dung lam
quan van » luan van, quan va, quan luan
van kiem » va kiem, van kien, van hieu
lan van » luan van, lang van, tan van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh dung lan van ((hieu soat) or (hieu suat)) ) or ( dinh duong quan van kiem soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung lan van ((hieu soat) OR (hieu suat)) ) OR ( dinh duong quan van kiem soat )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung lan van ((hieu soat) or (hieu suat)) ) or ( dinh duong quan van kiem soat ))*.