Perhaps you should try some spelling variations:
thanh phan » thanh pho, thanh san, thanh toan
hanh tranh » hanh trinh, hanh trang, lanh tranh
hieu sang » chieu sang, hieu lang, hieu quang
cua nhung » va nhung
doc hieu » toc thieu, hoc thieu, hoc hien
don ban » dong ban, do ban, con ban
doi ban » di ban, do ban, dong ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - ((hanh tranh) OR (canh tranh)) cua nhung ((don ban) OR (doi ban)) thanh phan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sang - ((hanh tranh) or (canh tranh)) cua nhung ((don ban) OR (doi ban)) thanh phan~".
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - ((hanh tranh) or (canh tranh)) cua nhung ((don ban) OR (doi ban)) thanh phan*.