Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » dung cong, thong cong, hang cong
toan thanh » tran thanh, hoan thanh, tan thanh
toan thang » toan thong, thanh thang, tran thanh
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung

You may be able to get more results by adjusting your search query.

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