Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
kiem soat » kiem toan
tinh quan » tinh quang, trinh quan, tin quan
hieu soat » hieu suat, hieu hoat, hieu luat
dung lan » dung luan, dung land, dung lam
kien hoa » dien hoa, tien hoa, kien ha
quan san » luan san, quan sat, quan van
van hieu » cao hieu
lan van » luan van, lang van, tan van
san van » tan van, luan van, tran van

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 ((kiem soat) OR (kien hoa)) ) OR ( tinh quan san van hieu soat ))~.
• Adding a wildcard symbol may retrieve word variants: (( tinh dung lan van ((kiem soat) or (kien hoa)) ) or ( tinh quan san van hieu soat ))*.