Perhaps you should try some spelling variations:
nhung cong » thong cong, hang cong, nhung don
hieu manh » chieu xanh, hieu nganh, dieu hanh
hanh tung » thanh tung, manh tung, hanh dung
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
anh tang » anh bang, anh dang, anh nang
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, 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: doc hieu manh - ((hanh tung) or (anh tang)) cua ((nhung cong) OR (dung cong)) dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu manh - ((hanh tung) OR (anh tang)) cua ((nhung cong) OR (dung cong)) dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu manh - ((hanh tung) or (anh tang)) cua ((nhung cong) OR (dung cong)) dan than cau".
• Adding a wildcard symbol may retrieve word variants: doc hieu manh - ((hanh tung) or (anh tang)) cua ((nhung cong) OR (dung cong)) dan than cau*.