Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu qua, diep quang
nhanh dang » nhan dang, nhanh dong, nhanh lang
hieu quan » hieu qua, lieu quan, thien quan
duong van » duong va, luong va, dang van
trong van » trong cac
dang vat » dang van, dong vat, dang nhat
vat dung » van dung, va dung, viet dung
tan cau » toan cau, van cau, tan ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu quang) OR (hieu quan)) - nhanh dang vat dung ((duong van) or (trong van)) tan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quang) OR (hieu quan)) - nhanh dang vat dung ((duong van) OR (trong van)) tan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quang) OR (hieu quan)) - nhanh dang vat dung ((duong van) or (trong van)) tan cau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quang) OR (hieu quan)) - nhanh dang vat dung ((duong van) or (trong van)) tan cau*.