Perhaps you should try some spelling variations:
luong quan » thong quan, duong qua
hieu suat » hieu luat, hieu qua
kiem soat » kiem toan
tin luong » tien luong, tin huong, tin tuong
dung tan » dung toan, duong tan, dung tai
quan van » luan van, quan va, quan luan
van bien » van tien, van hien, vat bien
tan van » tran van, tang van, luan van
bien so » bien doi

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: (( trinh dung tan van ((kiem soat) OR (hieu suat)) ) OR ( tin luong quan van bien so ))~.
• Adding a wildcard symbol may retrieve word variants: (( trinh dung tan van ((kiem soat) or (hieu suat)) ) or ( tin luong quan van bien so ))*.