Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien danh
thien anh » thien danh, tien anh, thien thanh
hanh hanh » hanh han, xanh hanh, nhanh thanh
cong san » cong tac
toan cau » toan cao, toan ban, toan tap
hanh va » hang va, hanh vi
va hang » van hang, va nang, va lang

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 (thien anh)) - hanh hanh va hang ((cong san) or (huong dan)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (thien anh)) - hanh hanh va hang ((cong san) OR (huong dan)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (thien anh)) - hanh hanh va hang ((cong san) or (huong dan)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (thien anh)) - hanh hanh va hang ((cong san) or (huong dan)) toan cau*.