Perhaps you should try some spelling variations:
thanh trung » thanh tung
chiet tach » chieu sach
nhung cong » thong cong, hang cong, nhung don
hoc chiet » hoc thiet, hoc nhiet, hoc hien
dung cong » dung trong
san phan » san pham, van phan, sat phan
phan cau » phan dau, phan cac, phan tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc chiet tach - ((thanh trung) or (canh tranh)) va ((nhung cong) OR (dung cong)) san phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - ((thanh trung) OR (canh tranh)) va ((nhung cong) OR (dung cong)) san phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chiet tach - ((thanh trung) or (canh tranh)) va ((nhung cong) OR (dung cong)) san phan cau".
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - ((thanh trung) or (canh tranh)) va ((nhung cong) OR (dung cong)) san phan cau*.