Perhaps you should try some spelling variations:
thanh tung » thanh cong
duong cong » dung cong, luong cong, duong trong
hieu lang » chieu sang, hieu quang, nhieu tang
va duong » van duong, va tuong, va huong
tap toan » tap quan, bai toan
tap doan » tap quan
tung va » trung va, tuong va, dung va
tinh » trinh, dinh, minh

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((trieu tinh) or (hieu lang)) - thanh tung va duong cong ((tap toan) OR (tap doan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((trieu tinh) OR (hieu lang)) - thanh tung va duong cong ((tap toan) OR (tap doan)) cao*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((trieu tinh) or (hieu lang)) - thanh tung va duong cong ((tap toan) OR (tap doan)) cao*".