Perhaps you should try some spelling variations:
hien hanh » dieu hanh
thuong va » truong va, thong va, thuong mai
lang cong » dang cong, bang cong, hang cong
dung cong » dung trong
luong va » dung va
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: hoc hien hanh - thanh ((luong va) or (thuong va)) ((lang cong) or (dung cong)) dan than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien hanh - thanh ((luong va) OR (thuong va)) ((lang cong) OR (dung cong)) dan than tap.
• Adding a wildcard symbol may retrieve word variants: hoc hien hanh - thanh ((luong va) or (thuong va)) ((lang cong) or (dung cong)) dan than tap*.