Perhaps you should try some spelling variations:
doanh doanh » toan doanh, doanh hoan, doanh thanh
doanh quang » doan quang, doanh quan, doanh luan
hieu lang » chieu sang, hieu quang, nhieu tang
bang cong » dang cong, bang song, hang cong
tan nhanh » tai nhanh, tan nhan, tan thanh
hoc hieu » hoc thieu, hoc hien, doc hieu
nhanh va » hanh va, nhan va, nhanh ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - doanh doanh quang ((han tong) or (bang cong)) tan nhanh va~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - doanh doanh quang ((han tong) OR (bang cong)) tan nhanh va.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - doanh doanh quang ((han tong) or (bang cong)) tan nhanh va*.