Perhaps you should try some spelling variations:
luat quang » luat quan, xuat quang, chat quang
khong quan » thong quan, hong quan, thong quang
khung luan » chung luan, dung luan, hang luan
quang van » quang ban, quan van, quang uan
hieu suat » hieu luat, hieu qua
tien soat » trien hoat, thien hoat, kiem soat
van hieu » cao hieu
van tien » toan tien, van tuan

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

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