Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » dung cong, thong cong, hang cong
hieu cach » hieu cac, chieu sach, hieu ca
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung
toc hieu » toc thieu, doc hieu, hoc thieu
dan toan » van toan, dan than, manh toan
van tuan » van quan, van ban, anh tuan

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

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