Perhaps you should try some spelling variations:
chieu sach » chiet tach, chieu sang, chieu xanh
hanh trinh » canh tranh, hanh chinh
vai nhung » va nhung, voi nhung, vap nhung
vi nhung » voi nhung, va nhung, ve nhung
cong san » cong tac
san than » sang than, san thanh, ban than
than cau » toan cau, phan cau, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sach) or (chinh sach)) - hanh trinh ((vi nhung) OR (vai nhung)) cong san than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (chinh sach)) - hanh trinh ((vi nhung) OR (vai nhung)) cong san than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) or (chinh sach)) - hanh trinh ((vi nhung) OR (vai nhung)) cong san than cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (chinh sach)) - hanh trinh ((vi nhung) OR (vai nhung)) cong san than cau*.