Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
hang nhung » sang nhung, hanh nhung, hong nhung
hieu manh » hieu nganh, dieu hanh, hien hanh
hanh tang » hanh trang, anh tang, hanh mang
tang cua » mang cua, hang cua, tang luan
cua hang » cua dang, cua nhung, cua cong
tap toan » tap doan, tap quan
bai toan » bai tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu manh) or (chieu xanh)) - hanh tang cua hang nhung ((tap toan) OR (bai toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu manh) OR (chieu xanh)) - hanh tang cua hang nhung ((tap toan) OR (bai toan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu manh) or (chieu xanh)) - hanh tang cua hang nhung ((tap toan) OR (bai toan)) cao".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu manh) or (chieu xanh)) - hanh tang cua hang nhung ((tap toan) OR (bai toan)) cao*.