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
cua thong » cua thuong, cua khong, cua tong
ban thanh » ban hanh, ban hang
thanh cau » thanh chau, thanh mau, nhanh cau
hoc hieu » hoc thieu, hoc hien, doc hieu
cong ban » cong bang, cong san, cong tan

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