Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
hang cong » dang cong, hang nong, bang cong
trinh ve » trinh va, trinh vi, trinh viet
trinh he » trinh han, trinh hoa, trinh thi
cong san » cong tac
san toan » van toan, dan toan, manh 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 ((chieu xanh) or (chieu sang)) - hanh ((trinh ve) OR (trinh he)) hang cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu xanh) OR (chieu sang)) - hanh ((trinh ve) OR (trinh he)) hang cong san toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu xanh) or (chieu sang)) - hanh ((trinh ve) OR (trinh he)) hang cong san toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) or (chieu sang)) - hanh ((trinh ve) OR (trinh he)) hang cong san toan cau*.