Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan tap » toan ban
va hanh » van hanh, va thanh, va danh
va lang » va nang, hoa lang

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 ((thieu xanh) OR (chieu xanh)) - thanh trung ((va hanh) OR (va lang)) cong tac toan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (chieu xanh)) - thanh trung ((va hanh) or (va lang)) cong tac toan tap~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (chieu xanh)) - thanh trung ((va hanh) or (va lang)) cong tac toan tap*.