Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
nang sang » nang song, nong san
trong san » trong cac, dong san, trong ca
doc hieu » toc thieu, hoc thieu, hoc hien
qua dung » quang dung, qua song, qua cong
cong san » cong tac
than cap » khan cap, thanh lap, thanh cac

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 manh - nang sang ((qua dung) or (su dung)) ((trong san) OR (cong san)) than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu manh - nang sang ((qua dung) OR (su dung)) ((trong san) OR (cong san)) than cap*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu manh - nang sang ((qua dung) or (su dung)) ((trong san) OR (cong san)) than cap*".