Perhaps you should try some spelling variations:
thanh tung » thanh cong
thong cong » trong cong, tong cong, phong chong
hieu lang » chieu sang, hieu quang, nhieu tang
tung tuan » trung tuan, hung tuan, quang tuan
hoc hieu » hoc thieu, hoc hien, doc hieu
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh

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 - thanh tung tuan ((thong cong) or (thong thong)) ((dan toan) OR (van toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - thanh tung tuan ((thong cong) OR (thong thong)) ((dan toan) OR (van toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - thanh tung tuan ((thong cong) or (thong thong)) ((dan toan) OR (van toan)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - thanh tung tuan ((thong cong) or (thong thong)) ((dan toan) OR (van toan)) cau*.