Perhaps you should try some spelling variations:
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
hieu manh » chieu xanh, hieu nganh, hien hanh
hanh tang » hanh trang, anh tang, hanh mang
tang cua » mang cua, hang cua, tang luan
san chan » san chang, dan chan, san chay
chan cau » phan cau, can cau, chinh cau

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) OR (dieu hanh)) - hanh tang cua ((nhung cong) or (thong cong)) san chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu manh) OR (dieu hanh)) - hanh tang cua ((nhung cong) OR (thong cong)) san chan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu manh) OR (dieu hanh)) - hanh tang cua ((nhung cong) or (thong cong)) san chan cau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu manh) OR (dieu hanh)) - hanh tang cua ((nhung cong) or (thong cong)) san chan cau*.