Perhaps you should try some spelling variations:
chieu xanh » chieu sang, chieu tinh, hieu manh
chieu sach » chinh sach, chiet tach, chieu sang
hanh trinh » canh tranh, hanh chinh
trinh dap » trinh lap, trinh da, trinh dan
dap nhung » vap nhung, va nhung, dap ung
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
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 sach)) - hanh trinh dap nhung ((cong dan) OR (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu xanh) OR (chieu sach)) - hanh trinh dap nhung ((cong dan) OR (cong san)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu xanh) or (chieu sach)) - hanh trinh dap nhung ((cong dan) OR (cong san)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) or (chieu sach)) - hanh trinh dap nhung ((cong dan) OR (cong san)) toan cau*.