Perhaps you should try some spelling variations:
thanh trung » thanh tung
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
hieu van » hieu va, thien van, lieu va
va thong » va thuong, va phuong, he thong
cong tac » cong ty
tac hang » tac vang, bac thang, tac chong
hang cau » hang dau, hang ca, nhung cau

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 lang) or (hieu van)) - ((thanh trung) or (canh tranh)) va thong cong tac hang cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu van)) - ((thanh trung) OR (canh tranh)) va thong cong tac hang cau.
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (hieu van)) - ((thanh trung) or (canh tranh)) va thong cong tac hang cau*.