Perhaps you should try some spelling variations:
thanh trung » thanh tung
thong cong » trong cong, tong cong, thong thong
hieu cach » chieu sach, hieu ca, biet cach
trung cua » truong cua, trung tuan, trung cap
cua thong » cua thuong, cua khong, cua tong
hieu cac » hieu luc, hieu va, hieu van
dan than » ban than, van than, dan toan
dan chan » dan gian, dan ca, van chat

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

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