Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chieu sang, chieu xanh
dung cong » dung trong
trung ha » trung hoc, trung tam, trung cap
cong sat » cong suat, cong san, cong hat
phan dau » phan tu
hang dau » hang va, hang tai
ha dung » hai dung, kha dung, nha dung

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) OR (chieu sach)) - thanh trung ha dung cong sat ((phan dau) or (hang dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chiet tach) OR (chieu sach)) - thanh trung ha dung cong sat ((phan dau) OR (hang dau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chiet tach) OR (chieu sach)) - thanh trung ha dung cong sat ((phan dau) or (hang dau))".
• Adding a wildcard symbol may retrieve word variants: hoc ((chiet tach) OR (chieu sach)) - thanh trung ha dung cong sat ((phan dau) or (hang dau))*.