Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
hanh trang » thanh trung, canh tranh, hanh trinh
thong cong » trong cong, tong cong, thong thong
tieu xanh » tieu danh, dieu hanh, tien anh
trang va » tran van, hang va
va thong » va thuong, va phuong, he thong
bai toan » bai tap
tap doan » tap quan

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((tieu xanh) OR (chieu xanh)) - hanh trang va thong cong ((bai toan) OR (tap doan)) cau~".
• Adding a wildcard symbol may retrieve word variants: theo ((tieu xanh) OR (chieu xanh)) - hanh trang va thong cong ((bai toan) OR (tap doan)) cau*.