Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, thong cong, hang cong
hieu xanh » hieu manh, hieu nganh, dieu hanh
cua nhung » va nhung
cong cua » cong cu, dong cua, huong cua
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban

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 xanh) OR (chieu xanh)) - thanh cong cua nhung cong bai toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu xanh) OR (chieu xanh)) - thanh cong cua nhung cong bai toan ban".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) OR (chieu xanh)) - thanh cong cua nhung cong bai toan ban*.