Perhaps you should try some spelling variations:
luong quan » thong quan, duong qua
dung quang » dang quang, dung quan, luong quang
tinh huong » dinh huong, tinh quang, anh huong
huong quan » cuong quan, vuong quan, hong quan
hieu soat » hieu suat, hieu hoat, hieu luat
kiem soat » kiem toan
van hieu » cao hieu
quan van » luan van, quan va, quan luan
van kiem » va kiem, van kien, van hien

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

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