Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, hieu lang
hoc chieu » hoc thieu, ho chieu, hoc hien
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.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc chieu sang - thanh trung ((va hanh) or (va lang)) cong tac toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chieu sang - thanh trung ((va hanh) OR (va lang)) cong tac toan tap.
• Adding a wildcard symbol may retrieve word variants: hoc chieu sang - thanh trung ((va hanh) or (va lang)) cong tac toan tap*.