Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
nhung cong » dung cong, thong cong, hang cong
trong van » trong cac
tang van » dang van, hoang van, tang luan
cong san » cong tac
san than » sang than, san thanh, ban 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: toc thieu xanh - hanh ((tang van) or (trong van)) nhung cong san than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu xanh - hanh ((tang van) OR (trong van)) nhung cong san than tap.
• Adding a wildcard symbol may retrieve word variants: toc thieu xanh - hanh ((tang van) or (trong van)) nhung cong san than tap*.