Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
hieu xanh » chieu xanh, hieu manh, dieu hanh
hanh tran » hanh trang, thanh tran, hanh tram
van thong » van thuong, van phong, van thang
va thong » va thuong, va phuong, he thong
cong san » cong tac
san hang » san chang, ban hang, van hang
hang dau » hang va, hang tai

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 tran ((van thong) OR (va thong)) cong san hang dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu xanh) OR (hieu nganh)) - hanh tran ((van thong) OR (va thong)) cong san hang dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu xanh) or (hieu nganh)) - hanh tran ((van thong) OR (va thong)) cong san hang dau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) or (hieu nganh)) - hanh tran ((van thong) OR (va thong)) cong san hang dau*.