Perhaps you should try some spelling variations:
doanh xuan » doanh luan, doanh xuat, doan xuan
hanh doanh » hang doanh, chinh doanh, doanh doanh
xuan trung » xuan truong, quang trung, doan trung
hieu manh » chieu xanh, hieu nganh, hien hanh
uong tan » duong tan, vuong tan, cong tan
tran tan » tran tuan, tran thanh, trang tuan
tran van » luan van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((dieu hanh) or (hieu manh)) - hanh doanh xuan trung uong tan ((tran tan) or (tran van))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((dieu hanh) OR (hieu manh)) - hanh doanh xuan trung uong tan ((tran tan) OR (tran van)).
• Adding a wildcard symbol may retrieve word variants: doc ((dieu hanh) or (hieu manh)) - hanh doanh xuan trung uong tan ((tran tan) or (tran van))*.