Perhaps you should try some spelling variations:
thong cong » tong cong, thong thong, phong chong
hieu lang » chieu sang, hieu quang, nhieu tang
tranh qua » thanh qua, trinh qua, tranh quang
tranh cua » doanh cua, manh cua
san toan » van toan, dan toan, manh toan
toan ban » van ban
ho hieu » ho chieu, hoi hieu, nho hieu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - canh ((tranh qua) OR (tranh cua)) ((thong cong) OR (trong cong)) san toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - canh ((tranh qua) or (tranh cua)) ((thong cong) OR (trong cong)) san toan ban~".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - canh ((tranh qua) or (tranh cua)) ((thong cong) OR (trong cong)) san toan ban*.