Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
dang cung » dang cuong, dang cong, dang hung
doc hieu » toc thieu, hoc thieu, hoc hien
cua dang » cua cong, cua ban
cung bai » cuong bai, dung bai, nhung bai
bai toan » bai tap
toan tap » toan 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 - ((thanh tung) or (thanh cong)) cua dang cung bai toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - ((thanh tung) OR (thanh cong)) cua dang cung bai toan tap*.