Perhaps you should try some spelling variations:
thieu quang » thien quan, trien quang, hieu quan
thanh trung » thanh tung
hieu quang » hieu quan, hieu qua, diep quang
nong danh » cong danh, dong danh, nang danh
trung va » truong va, trang va, trung ha
nong dan » cong dan, nong san, nguong dan
toan tap » toan ban
va hang » van hang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((hieu quang) OR (thieu quang)) - thanh trung va hang ((nong danh) or (nong dan)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((hieu quang) OR (thieu quang)) - thanh trung va hang ((nong danh) OR (nong dan)) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((hieu quang) OR (thieu quang)) - thanh trung va hang ((nong danh) or (nong dan)) toan tap".
• Adding a wildcard symbol may retrieve word variants: doi ((hieu quang) OR (thieu quang)) - thanh trung va hang ((nong danh) or (nong dan)) toan tap*.