Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
toan thanh » tran thanh, hoan thanh, toan thang
hieu lang » chieu sang, nhieu tang, hieu van
trung cua » truong cua, trung tuan, trung cap
thanh cau » thanh chau, thanh mau, nhanh 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 quang)) - thanh trung cua ((nhung cong) OR (thong cong)) toan thanh cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu quang)) - thanh trung cua ((nhung cong) OR (thong cong)) toan thanh cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) or (hieu quang)) - thanh trung cua ((nhung cong) OR (thong cong)) toan thanh cau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (hieu quang)) - thanh trung cua ((nhung cong) OR (thong cong)) toan thanh cau*.