Perhaps you should try some spelling variations:
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
hanh cong » hang cong, hanh dong, nhanh chong
trong van » trong cac
san dung » van dung, dan dung, tan dung
van toan » van tuan, van tan, van thanh
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)) - ((hanh cong) or (thanh cong)) san dung trong van toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu xanh)) - ((hanh cong) OR (thanh cong)) san dung trong van toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (chieu xanh)) - ((hanh cong) or (thanh cong)) san dung trong van toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (chieu xanh)) - ((hanh cong) or (thanh cong)) san dung trong van toan cau*.