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
qua dung » quang dung, qua song, qua cong
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cau » 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 ((thieu xanh) or (chieu xanh)) - thanh trung ((qua dung) OR (su dung)) cong tan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu xanh)) - thanh trung ((qua dung) OR (su dung)) cong tan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) or (chieu xanh)) - thanh trung ((qua dung) OR (su dung)) cong tan toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (chieu xanh)) - thanh trung ((qua dung) OR (su dung)) cong tan toan cau*.