Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
tien thanh » tien thinh, tran thanh, den thanh
hanh trinh » canh tranh, hanh chinh
trinh luan » trinh luat, trinh quan, trinh han
phung cong » nhung cong, phong cong, nhung chong
hung cong » nhung cong, hung cuong, dung cong
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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: hoc ((chieu sach) OR (tien thanh)) - hanh trinh luan ((hung cong) OR (phung cong)) dan than cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) or (tien thanh)) - hanh trinh luan ((hung cong) OR (phung cong)) dan than cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (tien thanh)) - hanh trinh luan ((hung cong) OR (phung cong)) dan than cau*.