Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
hanh tranh » canh tranh, hanh trinh, hanh trang
hien xanh » hien hanh, hien nhanh, hien khanh
tranh va » tranh van, trang va, trinh va
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
than tu » thanh tu, thang tu, phan tu

You may be able to get more results by adjusting your search query.

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