Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
hieu quan » hieu qua, lieu quan, thien quan
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung
cong toan » cong tan, cong hoan, cong tuan
thanh cau » thanh chau, thanh mau, thanh ca
nhanh cau » nhanh cay, thanh chau, nhanh ha

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