Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hanh trang » thanh trung, hanh trinh, minh trang
nhung cong » thong cong, hang cong, nhung don
doi chieu » doc hieu, doi chi, ho chieu
dung cong » dung trong
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chieu sach - ((hanh trang) or (canh tranh)) va ((nhung cong) OR (dung cong)) dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - ((hanh trang) OR (canh tranh)) va ((nhung cong) OR (dung cong)) dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chieu sach - ((hanh trang) or (canh tranh)) va ((nhung cong) OR (dung cong)) dan toan cau".
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - ((hanh trang) or (canh tranh)) va ((nhung cong) OR (dung cong)) dan toan cau*.