Perhaps you should try some spelling variations:
hien hanh » dieu hanh
hang hang » nang hang, cang thang, hung thang
hang cong » dang cong, hang nong, bang cong
dung cong » dung trong
dien anh » tieng anh, dien dan
dan than » dan chan, ban than, van than
than cao » toan cao, thai cao, than cap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((dien anh) or (hien hanh)) - hang hang va ((hang cong) or (dung cong)) dan than cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((dien anh) OR (hien hanh)) - hang hang va ((hang cong) OR (dung cong)) dan than cao.
• Adding a wildcard symbol may retrieve word variants: hoc ((dien anh) or (hien hanh)) - hang hang va ((hang cong) or (dung cong)) dan than cao*.