Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
hanh tang » hanh trang, anh tang, hanh mang
dang cong » dung cong
doc hieu » toc thieu, hoc thieu, hoc hien
tang cua » mang cua, hang cua, tang luan
cua dang » cua cong, cua ban
tap toan » tap doan, bai toan
tap quan » hai quan

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 - hanh tang cua dang cong ((tap toan) or (((tap quan) or (tac quan)))) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh tang cua dang cong ((tap toan) OR (((tap quan) OR (tac quan)))) cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh tang cua dang cong ((tap toan) or (((tap quan) or (tac quan)))) cao*.