Perhaps you should try some spelling variations:
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
canh trinh » canh tranh, hanh trinh, canh tinh
trinh han » trinh quan
han hung » phan hung, van hung, han ung
cong tan » cong tac, cong san, cong thanh
chan cau » phan cau, can cau, chinh cau

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 ((thieu xanh) OR (chieu xanh)) - canh trinh han hung ((huong dan) OR (cong tan)) chan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (chieu xanh)) - canh trinh han hung ((huong dan) or (cong tan)) chan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (chieu xanh)) - canh trinh han hung ((huong dan) or (cong tan)) chan cau*.