Perhaps you should try some spelling variations:
quang quan » quang tuan, quang uan, quan quan
tinh dung » trinh dung, tin dung, tinh huong
kiem soat » kiem toan
hieu soat » hieu hoat, hieu luat, hieu so
hieu suat » hieu luat, hieu qua
dung lan » dung luan, dung land, dung lam
van kiem » va kiem, van kien, van hieu
quan van » luan van, quan va, quan luan
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 kiem soat ) or ( tinh quang quan van ((hieu soat) or (hieu suat)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung lan van kiem soat ) OR ( tinh quang quan van ((hieu soat) OR (hieu suat)) )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung lan van kiem soat ) or ( tinh quang quan van ((hieu soat) or (hieu suat)) ))*.