Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu cach » hieu cac, chieu sach, hieu ca
hoc hieu » hoc thieu, hoc hien, doc hieu
trung va » truong va, trang va, trung ha
cong van » cong vang, song van, cong tan
cong san » cong tac
than cau » toan cau, phan cau, than cap
phan lap » phan dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu cach - thanh trung va nhung ((cong van) or (cong san)) ((than cau) or (phan lap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu cach - thanh trung va nhung ((cong van) OR (cong san)) ((than cau) OR (phan lap)).
• Adding a wildcard symbol may retrieve word variants: hoc hieu cach - thanh trung va nhung ((cong van) or (cong san)) ((than cau) or (phan lap))*.