Perhaps you should try some spelling variations:
quang quan » quang tuan, quang uan, quan quan
dung quang » dang quang, dung quan, luong quang
thien hoat » trien hoat, thien thuat, tien hoa
quang van » quang ban, quang uan, quang va
hieu suat » hieu luat, hieu qua
kiem soat » kiem toan
van hieu » cao hieu
quan van » luan van, quan va, quan luan

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

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