Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
hieu xanh » chieu xanh, hieu manh, dieu hanh
dung cong » dung trong
chinh ta » chinh tai, chinh va, chinh tri
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan cau » toan cao, toan ban, toan tap
ta dung » tac dung, tan dung, tao dung

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 xanh) or (hieu nganh)) - hanh chinh ta dung cong san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu xanh) OR (hieu nganh)) - hanh chinh ta dung cong san toan cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) or (hieu nganh)) - hanh chinh ta dung cong san toan cau*.