Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » dung cong, thong cong, hang cong
hieu cach » chieu sach, hieu ca, biet cach
trung voi » trung moi, trung vi, trung vo
voi nhung » gioi nhung, va nhung, thi nhung
hieu cac » hieu luc, hieu va, hieu van
dan than » dan chan, ban than, van than
van hang » van khang, van hoang, van thang

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu cach) OR (hieu cac)) - thanh trung voi nhung cong ((dan than) OR (van hang)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu cach) OR (hieu cac)) - thanh trung voi nhung cong ((dan than) or (van hang)) cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu cach) OR (hieu cac)) - thanh trung voi nhung cong ((dan than) or (van hang)) cau*.