Perhaps you should try some spelling variations:
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, thong cong, hang cong
trinh vat » trinh van, trinh luat, sinh vat
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap
tinh va » tich va, trinh van, tinh gia

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