Perhaps you should try some spelling variations:
thanh tung » thanh cong
hieu lang » chieu sang, hieu quang, nhieu tang
tong cong » trong cong, dung cong, dang cong
cong cong » cong dong, trong cong, dung cong
tung cua » trung cua, tuong cua, dung cua
dan phan » doan phan, dan chan, van phan
phan cac » nhan cach, phan dau, phan lap

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chinh sach) or (hieu lang)) - thanh tung cua ((tong cong) OR (cong cong)) dan phan cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chinh sach) OR (hieu lang)) - thanh tung cua ((tong cong) OR (cong cong)) dan phan cac.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chinh sach) or (hieu lang)) - thanh tung cua ((tong cong) OR (cong cong)) dan phan cac".
• Adding a wildcard symbol may retrieve word variants: theo ((chinh sach) or (hieu lang)) - thanh tung cua ((tong cong) OR (cong cong)) dan phan cac*.