Perhaps you should try some spelling variations:
thanh trung » thanh tung
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung
bien cac » vien cac, dien cac, bien ca
hieu cua » hieu qua, dieu cua, bieu cua
cong tac » cong ty
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((bien cac) or (hieu cua)) - thanh trung cua nhung ((cong san) or (cong tac)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((bien cac) OR (hieu cua)) - thanh trung cua nhung ((cong san) OR (cong tac)) toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((bien cac) or (hieu cua)) - thanh trung cua nhung ((cong san) or (cong tac)) toan cao*.