Perhaps you should try some spelling variations:
thuong dong » phuong dong, tuong dong, chuong dong
hieu xanh » chieu xanh, hieu manh, hieu nganh
tang luan » dung luan
doc hieu » toc thieu, hoc thieu, hoc hien
than cua » nhan cua, thai cua, ban cua
dong dan » dong danh, duong dan, dong san
dan than » dan chan, ban than, van than
than tap » toan tap, han tap, phan 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 xanh - hanh ((than cua) or (tang luan)) thuong dong dan than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh ((than cua) OR (tang luan)) thuong dong dan than tap.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh ((than cua) or (tang luan)) thuong dong dan than tap*.