Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
chieu sang » chieu sach, chieu xanh, hieu lang
hanh trang » thanh trung, canh tranh, hanh trinh
trang va » tran van, hang va
va thong » va thuong, va phuong, he thong
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
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 sang)) - hanh trang va thong ((cong dan) OR (cong san)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu sang)) - hanh trang va thong ((cong dan) OR (cong san)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) or (chieu sang)) - hanh trang va thong ((cong dan) OR (cong san)) toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (chieu sang)) - hanh trang va thong ((cong dan) OR (cong san)) toan cao*.