Perhaps you should try some spelling variations:
thanh trung » thanh tung
theo sach » thuoc sach, te sach, theo lich
trung cao » truong cao, trung cap, trung co
dang cong » dung cong
hieu cua » hieu qua, dieu cua, bieu cua
dan than » dan chan, ban than, dan toan
van than » van thanh, van thang, van tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((theo sach) or (hieu cua)) - thanh trung cao dang cong ((dan than) or (van than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((theo sach) OR (hieu cua)) - thanh trung cao dang cong ((dan than) OR (van than)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((theo sach) or (hieu cua)) - thanh trung cao dang cong ((dan than) or (van than)) cau*.